diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/feign/pojo.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/feign/pojo.mustache
index 515b3783560a..27d2c3b9eea3 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/feign/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/feign/pojo.mustache
@@ -318,10 +318,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
    * (except the first line).
    */
   private{{#jsonb}} static{{/jsonb}} String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 {{#supportUrlQuery}}
 
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/jersey2/AbstractOpenApiSchema.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/jersey2/AbstractOpenApiSchema.mustache
index 8e5c32da75ad..4ad93f1c4230 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/jersey2/AbstractOpenApiSchema.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/jersey2/AbstractOpenApiSchema.mustache
@@ -97,10 +97,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/jersey2/pojo.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/jersey2/pojo.mustache
index 2f4bac6a7da3..57f01e0b731a 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/jersey2/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/jersey2/pojo.mustache
@@ -338,10 +338,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 {{#parcelableModel}}
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/jersey3/AbstractOpenApiSchema.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/jersey3/AbstractOpenApiSchema.mustache
index 8e5c32da75ad..4ad93f1c4230 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/jersey3/AbstractOpenApiSchema.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/jersey3/AbstractOpenApiSchema.mustache
@@ -97,10 +97,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/jersey3/pojo.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/jersey3/pojo.mustache
index 2f4bac6a7da3..57f01e0b731a 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/jersey3/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/jersey3/pojo.mustache
@@ -338,10 +338,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 {{#parcelableModel}}
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/microprofile/pojoOverrides.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/microprofile/pojoOverrides.mustache
index 12cc98045c74..16aed160795b 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/microprofile/pojoOverrides.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/microprofile/pojoOverrides.mustache
@@ -63,8 +63,5 @@
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/native/AbstractOpenApiSchema.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/native/AbstractOpenApiSchema.mustache
index 8369ee7285e0..d6ba2626a1dc 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/native/AbstractOpenApiSchema.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/native/AbstractOpenApiSchema.mustache
@@ -95,10 +95,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/native/pojo.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/native/pojo.mustache
index abdf16d12009..4b16560c0c0f 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/native/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/native/pojo.mustache
@@ -342,10 +342,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 {{#supportUrlQuery}}
 
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/AbstractOpenApiSchema.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/AbstractOpenApiSchema.mustache
index 30e31cf33a35..f25abe7e5df7 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/AbstractOpenApiSchema.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/AbstractOpenApiSchema.mustache
@@ -94,10 +94,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/pojo.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/pojo.mustache
index cb19eb603679..08fe95493a6a 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/pojo.mustache
@@ -255,10 +255,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 {{#parcelableModel}}
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/restclient/pojo.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/restclient/pojo.mustache
index d72fdfee124d..9b11f8b2cc8b 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/restclient/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/restclient/pojo.mustache
@@ -364,10 +364,7 @@ public {{>sealed}}class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#v
    * (except the first line).
    */
   private{{#jsonb}} static{{/jsonb}} String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 {{#supportUrlQuery}}
 
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/pojo.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/pojo.mustache
index 5ec5d324e51f..44252c666e9b 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/pojo.mustache
@@ -364,10 +364,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
    * (except the first line).
    */
   private{{#jsonb}} static{{/jsonb}} String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 {{#supportUrlQuery}}
 
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/webclient/pojo.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/webclient/pojo.mustache
index c110998f0269..3b3eb4cf24b4 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/webclient/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/webclient/pojo.mustache
@@ -364,10 +364,7 @@ public {{>sealed}}class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#v
    * (except the first line).
    */
   private{{#jsonb}} static{{/jsonb}} String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 {{#supportUrlQuery}}
 
diff --git a/modules/openapi-generator/src/main/resources/Java/pojo.mustache b/modules/openapi-generator/src/main/resources/Java/pojo.mustache
index 0b5479df44b4..e09c78fa90f2 100644
--- a/modules/openapi-generator/src/main/resources/Java/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/pojo.mustache
@@ -363,10 +363,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
    * (except the first line).
    */
   private{{#jsonb}} static{{/jsonb}} String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 {{#supportUrlQuery}}
 
diff --git a/modules/openapi-generator/src/main/resources/JavaInflector/pojo.mustache b/modules/openapi-generator/src/main/resources/JavaInflector/pojo.mustache
index f4a0175bc0ef..e77d34e19ca5 100644
--- a/modules/openapi-generator/src/main/resources/JavaInflector/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaInflector/pojo.mustache
@@ -85,9 +85,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}} {{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/modules/openapi-generator/src/main/resources/JavaJaxRS/cxf-cdi/pojo.mustache b/modules/openapi-generator/src/main/resources/JavaJaxRS/cxf-cdi/pojo.mustache
index e741cb154b36..2c28a90cebb1 100644
--- a/modules/openapi-generator/src/main/resources/JavaJaxRS/cxf-cdi/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaJaxRS/cxf-cdi/pojo.mustache
@@ -105,9 +105,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}} {{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/modules/openapi-generator/src/main/resources/JavaJaxRS/cxf-ext/pojo.mustache b/modules/openapi-generator/src/main/resources/JavaJaxRS/cxf-ext/pojo.mustache
index a7266b00f008..693ededbb717 100644
--- a/modules/openapi-generator/src/main/resources/JavaJaxRS/cxf-ext/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaJaxRS/cxf-ext/pojo.mustache
@@ -166,9 +166,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}}{{#vendorExtensi
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/modules/openapi-generator/src/main/resources/JavaJaxRS/cxf/pojo.mustache b/modules/openapi-generator/src/main/resources/JavaJaxRS/cxf/pojo.mustache
index c3c6c52fecfa..5d5e99435702 100644
--- a/modules/openapi-generator/src/main/resources/JavaJaxRS/cxf/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaJaxRS/cxf/pojo.mustache
@@ -236,9 +236,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}}{{#vendorExtensi
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/modules/openapi-generator/src/main/resources/JavaJaxRS/libraries/jersey3/pojo.mustache b/modules/openapi-generator/src/main/resources/JavaJaxRS/libraries/jersey3/pojo.mustache
index 1908e1a357a3..fc9f6f1032c1 100644
--- a/modules/openapi-generator/src/main/resources/JavaJaxRS/libraries/jersey3/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaJaxRS/libraries/jersey3/pojo.mustache
@@ -134,9 +134,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}} {{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/modules/openapi-generator/src/main/resources/JavaJaxRS/pojo.mustache b/modules/openapi-generator/src/main/resources/JavaJaxRS/pojo.mustache
index 239f609106ee..c4475aba4270 100644
--- a/modules/openapi-generator/src/main/resources/JavaJaxRS/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaJaxRS/pojo.mustache
@@ -134,9 +134,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}} {{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/modules/openapi-generator/src/main/resources/JavaJaxRS/resteasy/eap/pojo.mustache b/modules/openapi-generator/src/main/resources/JavaJaxRS/resteasy/eap/pojo.mustache
index b581416b241a..63e775410d70 100644
--- a/modules/openapi-generator/src/main/resources/JavaJaxRS/resteasy/eap/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaJaxRS/resteasy/eap/pojo.mustache
@@ -76,9 +76,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}} {{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/modules/openapi-generator/src/main/resources/JavaJaxRS/resteasy/pojo.mustache b/modules/openapi-generator/src/main/resources/JavaJaxRS/resteasy/pojo.mustache
index 267544652093..cb1ce4039951 100644
--- a/modules/openapi-generator/src/main/resources/JavaJaxRS/resteasy/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaJaxRS/resteasy/pojo.mustache
@@ -77,9 +77,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}} {{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/modules/openapi-generator/src/main/resources/JavaJaxRS/spec/pojo.mustache b/modules/openapi-generator/src/main/resources/JavaJaxRS/spec/pojo.mustache
index 83970c86ca74..e6aee86d5804 100644
--- a/modules/openapi-generator/src/main/resources/JavaJaxRS/spec/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaJaxRS/spec/pojo.mustache
@@ -245,10 +245,7 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}} {{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 {{#generateBuilders}}{{^additionalProperties}}
diff --git a/modules/openapi-generator/src/main/resources/JavaPlayFramework/pojo.mustache b/modules/openapi-generator/src/main/resources/JavaPlayFramework/pojo.mustache
index 6e9b40a080f1..d2a6bcbad2ac 100644
--- a/modules/openapi-generator/src/main/resources/JavaPlayFramework/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaPlayFramework/pojo.mustache
@@ -139,9 +139,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}} {{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/modules/openapi-generator/src/main/resources/JavaSpring/pojo.mustache b/modules/openapi-generator/src/main/resources/JavaSpring/pojo.mustache
index 8a93fb054f1f..f76cf70a7b59 100644
--- a/modules/openapi-generator/src/main/resources/JavaSpring/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaSpring/pojo.mustache
@@ -335,10 +335,7 @@ public {{>sealed}}class {{classname}}{{#parent}} extends {{{parent}}}{{/parent}}
    * (except the first line).
    */
   private String toIndentedString({{>nullableAnnotation}}Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   {{/lombok.ToString}}
   {{#generateBuilders}}
diff --git a/modules/openapi-generator/src/main/resources/JavaVertXServer/pojo.mustache b/modules/openapi-generator/src/main/resources/JavaVertXServer/pojo.mustache
index f0b46718977e..4623ac21bd71 100644
--- a/modules/openapi-generator/src/main/resources/JavaVertXServer/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaVertXServer/pojo.mustache
@@ -63,9 +63,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}} {{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/modules/openapi-generator/src/main/resources/JavaVertXWebServer/pojo.mustache b/modules/openapi-generator/src/main/resources/JavaVertXWebServer/pojo.mustache
index f0b46718977e..4623ac21bd71 100644
--- a/modules/openapi-generator/src/main/resources/JavaVertXWebServer/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaVertXWebServer/pojo.mustache
@@ -63,9 +63,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}} {{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/modules/openapi-generator/src/main/resources/java-camel-server/pojo.mustache b/modules/openapi-generator/src/main/resources/java-camel-server/pojo.mustache
index 6f99ee322967..29b24f808e96 100644
--- a/modules/openapi-generator/src/main/resources/java-camel-server/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/java-camel-server/pojo.mustache
@@ -355,10 +355,7 @@ public class {{classname}}{{#parent}} extends {{{parent}}}{{/parent}}{{^parent}}
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   {{/lombok.ToString}}
   {{#generateBuilders}}
diff --git a/modules/openapi-generator/src/main/resources/java-dubbo/model.mustache b/modules/openapi-generator/src/main/resources/java-dubbo/model.mustache
index ba5efc7e40d1..449f45732f58 100644
--- a/modules/openapi-generator/src/main/resources/java-dubbo/model.mustache
+++ b/modules/openapi-generator/src/main/resources/java-dubbo/model.mustache
@@ -82,10 +82,7 @@ public class {{classname}} {{#parent}}extends {{{parent}}}{{/parent}}{{^parent}}
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 {{/model}}
diff --git a/modules/openapi-generator/src/main/resources/java-helidon/client/libraries/mp/pojo.mustache b/modules/openapi-generator/src/main/resources/java-helidon/client/libraries/mp/pojo.mustache
index d91b15d65b8b..7bc4e82f0217 100644
--- a/modules/openapi-generator/src/main/resources/java-helidon/client/libraries/mp/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/java-helidon/client/libraries/mp/pojo.mustache
@@ -148,9 +148,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}}{{#vendorExtensi
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/modules/openapi-generator/src/main/resources/java-helidon/client/libraries/se/pojo.mustache b/modules/openapi-generator/src/main/resources/java-helidon/client/libraries/se/pojo.mustache
index d91b15d65b8b..7bc4e82f0217 100644
--- a/modules/openapi-generator/src/main/resources/java-helidon/client/libraries/se/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/java-helidon/client/libraries/se/pojo.mustache
@@ -148,9 +148,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}}{{#vendorExtensi
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/modules/openapi-generator/src/main/resources/java-helidon/common/pojo.mustache b/modules/openapi-generator/src/main/resources/java-helidon/common/pojo.mustache
index e1c6a4353774..9df1ab88f4bd 100644
--- a/modules/openapi-generator/src/main/resources/java-helidon/common/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/java-helidon/common/pojo.mustache
@@ -115,9 +115,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}} {{#vendorExtens
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
diff --git a/modules/openapi-generator/src/main/resources/java-helidon/server/libraries/mp/pojo.mustache b/modules/openapi-generator/src/main/resources/java-helidon/server/libraries/mp/pojo.mustache
index 0767d80a52de..2215bbbbacf9 100644
--- a/modules/openapi-generator/src/main/resources/java-helidon/server/libraries/mp/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/java-helidon/server/libraries/mp/pojo.mustache
@@ -154,9 +154,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}}{{#vendorExtensi
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/modules/openapi-generator/src/main/resources/java-helidon/server/libraries/se/pojo.mustache b/modules/openapi-generator/src/main/resources/java-helidon/server/libraries/se/pojo.mustache
index e5c598c4febd..d23454799819 100644
--- a/modules/openapi-generator/src/main/resources/java-helidon/server/libraries/se/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/java-helidon/server/libraries/se/pojo.mustache
@@ -115,9 +115,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}} {{#vendorExtens
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
diff --git a/modules/openapi-generator/src/main/resources/java-micronaut/common/model/pojo.mustache b/modules/openapi-generator/src/main/resources/java-micronaut/common/model/pojo.mustache
index fc2c137c586b..27a07f4cc768 100644
--- a/modules/openapi-generator/src/main/resources/java-micronaut/common/model/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/java-micronaut/common/model/pojo.mustache
@@ -292,10 +292,7 @@ Declare the class with extends and implements
      * (except the first line).
      */
     private{{#jsonb}} static{{/jsonb}} String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     {{#parcelableModel}}
diff --git a/modules/openapi-generator/src/main/resources/java-msf4j-server/pojo.mustache b/modules/openapi-generator/src/main/resources/java-msf4j-server/pojo.mustache
index a9bd1c7e689b..671296b11293 100644
--- a/modules/openapi-generator/src/main/resources/java-msf4j-server/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/java-msf4j-server/pojo.mustache
@@ -130,9 +130,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}} {{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/modules/openapi-generator/src/main/resources/java-pkmst/pojo.mustache b/modules/openapi-generator/src/main/resources/java-pkmst/pojo.mustache
index 687e552b9338..61092b6b02db 100644
--- a/modules/openapi-generator/src/main/resources/java-pkmst/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/java-pkmst/pojo.mustache
@@ -134,9 +134,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}} {{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/modules/openapi-generator/src/main/resources/java-undertow-server/pojo.mustache b/modules/openapi-generator/src/main/resources/java-undertow-server/pojo.mustache
index 6af043aa9906..7a31a1121306 100644
--- a/modules/openapi-generator/src/main/resources/java-undertow-server/pojo.mustache
+++ b/modules/openapi-generator/src/main/resources/java-undertow-server/pojo.mustache
@@ -66,9 +66,6 @@ public class {{classname}} {{#parent}}extends {{{.}}}{{/parent}} {{#vendorExtens
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Bird.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Bird.java
index 58c19e3a9da1..cd15f192e838 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Bird.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Bird.java
@@ -130,10 +130,7 @@ public class Bird {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Category.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Category.java
index a6eb89953ae3..da999f04674f 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Category.java
@@ -130,10 +130,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/DataQuery.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/DataQuery.java
index e7d04f7d71f6..14f5ed8965f8 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/DataQuery.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/DataQuery.java
@@ -182,10 +182,7 @@ public class DataQuery extends Query {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/DefaultValue.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/DefaultValue.java
index 761efdc14bbb..d625990d7d4f 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/DefaultValue.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/DefaultValue.java
@@ -466,10 +466,7 @@ public class DefaultValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
index 03061fe520db..d8458d722c07 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
@@ -165,10 +165,7 @@ public class NumberPropertiesOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
index e43597fcf0c5..ef20b06e543e 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
@@ -316,10 +316,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Query.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Query.java
index bca4c8c1de76..9db4725345c1 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Query.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Query.java
@@ -178,10 +178,7 @@ public class Query {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Tag.java
index d5c43570c4de..2e20ad9caa9f 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Tag.java
@@ -130,10 +130,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
index e3e0ca836e9c..fe659c6863e0 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
@@ -99,10 +99,7 @@ public class TestFormObjectMultipartRequestMarker {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
index 59eafae6653a..bcbc00db0ead 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
@@ -195,10 +195,7 @@ public class TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
index ffd5de27bbd1..2ba847a8ab80 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
@@ -110,10 +110,7 @@ public class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Bird.java b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Bird.java
index c21a0caaca95..155e16f2ff21 100644
--- a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Bird.java
+++ b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Bird.java
@@ -117,10 +117,7 @@ public class Bird {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Category.java b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Category.java
index e2c68ad567a7..4371504d884a 100644
--- a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Category.java
@@ -117,10 +117,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/DataQuery.java b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/DataQuery.java
index 1053564ecaad..27ad7bf1b8e3 100644
--- a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/DataQuery.java
+++ b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/DataQuery.java
@@ -154,10 +154,7 @@ public class DataQuery extends Query {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/DefaultValue.java b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/DefaultValue.java
index 7557b6e78233..5101e7472b6b 100644
--- a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/DefaultValue.java
+++ b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/DefaultValue.java
@@ -412,10 +412,7 @@ public class DefaultValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
index d98088abe4a1..f0cd11adc85c 100644
--- a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
+++ b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
@@ -149,10 +149,7 @@ public class NumberPropertiesOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Pet.java
index 10c98bdcc7a0..34637a5d12be 100644
--- a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Pet.java
@@ -303,10 +303,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Query.java b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Query.java
index 1294ca6f3a0b..3e04328893a6 100644
--- a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Query.java
+++ b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Query.java
@@ -177,10 +177,7 @@ public class Query {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Tag.java
index ced9e83968c0..9d168e5633f4 100644
--- a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Tag.java
@@ -117,10 +117,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
index 0e42ee37345d..62871f63318b 100644
--- a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
+++ b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
@@ -88,10 +88,7 @@ public class TestFormObjectMultipartRequestMarker {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
index f5af2132533e..d3a1f1503ab6 100644
--- a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
+++ b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
@@ -175,10 +175,7 @@ public class TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
index 0051c3c792d9..9790e7666aec 100644
--- a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
+++ b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
@@ -99,10 +99,7 @@ public class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 35ac1b2f5819..808154668972 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -105,10 +105,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Bird.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Bird.java
index 0e746034a7ac..b5d375254d4d 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Bird.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Bird.java
@@ -133,10 +133,7 @@ public class Bird {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Category.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Category.java
index 0c968cefe45c..859f386fb21a 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Category.java
@@ -133,10 +133,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/DataQuery.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/DataQuery.java
index 18362f1654e0..728cdb584a9d 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/DataQuery.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/DataQuery.java
@@ -182,10 +182,7 @@ public class DataQuery extends Query {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/DefaultValue.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/DefaultValue.java
index 9b2adb274916..1c046310b446 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/DefaultValue.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/DefaultValue.java
@@ -459,10 +459,7 @@ public class DefaultValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
index fd43e3cdd577..e62149070d63 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
@@ -167,10 +167,7 @@ public class NumberPropertiesOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Pet.java
index cd5d5a399038..52b91f05bb7a 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Pet.java
@@ -314,10 +314,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Query.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Query.java
index ae06323a2f96..e7630f928f1b 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Query.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Query.java
@@ -180,10 +180,7 @@ public class Query {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Tag.java
index de0fa882485a..07dff46e497b 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Tag.java
@@ -133,10 +133,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
index 1dc669e1c66c..8f522b8022c4 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
@@ -102,10 +102,7 @@ public class TestFormObjectMultipartRequestMarker {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
index 1ee3fcb6b90a..6011dfa9be25 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
@@ -195,10 +195,7 @@ public class TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
index 238c85ef4ef7..8d2d8f3cde5f 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
@@ -112,10 +112,7 @@ public class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/Category.java b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/Category.java
index 2f90d4675b9b..55a15e17e24a 100644
--- a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/Category.java
+++ b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/Category.java
@@ -59,10 +59,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/ModelApiResponse.java b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/ModelApiResponse.java
index 147892210dc6..64af23f1ef07 100644
--- a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/ModelApiResponse.java
+++ b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/ModelApiResponse.java
@@ -59,10 +59,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/Order.java b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/Order.java
index 09f27297af83..cfc25afe05d5 100644
--- a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/Order.java
+++ b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/Order.java
@@ -59,10 +59,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/Pet.java b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/Pet.java
index 13fc9d2e3b05..d2b9767c885f 100644
--- a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/Pet.java
+++ b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/Pet.java
@@ -59,10 +59,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/Tag.java b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/Tag.java
index d709f002e67b..a5ced8a32a1c 100644
--- a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/Tag.java
+++ b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/Tag.java
@@ -59,10 +59,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/User.java b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/User.java
index 6956b3931b3c..710000f023a2 100644
--- a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/User.java
+++ b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/modelCopy/User.java
@@ -59,10 +59,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index b7b4e2cb1cbd..e7311fcf9dec 100644
--- a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -104,10 +104,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Category.java b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Category.java
index df6ce109d9a0..60f254881241 100644
--- a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Category.java
@@ -135,10 +135,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 6052f57f8d29..1767704447e2 100644
--- a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -161,10 +161,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Order.java b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Order.java
index 9ce63d625762..7d6f9aeefb85 100644
--- a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Order.java
@@ -294,10 +294,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Pet.java
index 40d7badfee37..4fc37fc17dcb 100644
--- a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Pet.java
@@ -318,10 +318,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Tag.java
index f35d3d071734..37b49f7c009c 100644
--- a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Tag.java
@@ -135,10 +135,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/User.java b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/User.java
index 7e605e17a8a5..ab39afb67296 100644
--- a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/User.java
@@ -291,10 +291,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 698f82921d7d..d8f647ad0d0d 100644
--- a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -104,10 +104,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Bird.java b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Bird.java
index 7489b0a67437..9e648d961d32 100644
--- a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Bird.java
+++ b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Bird.java
@@ -135,10 +135,7 @@ public class Bird {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Category.java b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Category.java
index f78f5dbd3c7f..013663e55dd2 100644
--- a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Category.java
@@ -135,10 +135,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/DataQuery.java b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/DataQuery.java
index 5f474d3786da..24709d0457a5 100644
--- a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/DataQuery.java
+++ b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/DataQuery.java
@@ -167,10 +167,7 @@ public class DataQuery extends Query {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/DefaultValue.java b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/DefaultValue.java
index f28b1bcc1737..24043e4e0da4 100644
--- a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/DefaultValue.java
+++ b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/DefaultValue.java
@@ -416,10 +416,7 @@ public class DefaultValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
index 2f087e769356..2477d4cee359 100644
--- a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
+++ b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
@@ -164,10 +164,7 @@ public class NumberPropertiesOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java
index 0b29fcbb4971..9f54e895f7bd 100644
--- a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java
@@ -313,10 +313,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Query.java b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Query.java
index 3bb35aeb690f..daf4a8077fb8 100644
--- a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Query.java
+++ b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Query.java
@@ -199,10 +199,7 @@ public class Query {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Tag.java
index f7d5c31cc9b3..617a165c476e 100644
--- a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Tag.java
@@ -135,10 +135,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
index 0ec3cf1f1d97..125b020eb50e 100644
--- a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
+++ b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
@@ -109,10 +109,7 @@ public class TestFormObjectMultipartRequestMarker {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
index 3862ce6c6012..d3f637fa26ab 100644
--- a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
+++ b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
@@ -187,10 +187,7 @@ public class TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
index 23e14652b76c..15e5ffc33cdc 100644
--- a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
+++ b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
@@ -119,10 +119,7 @@ public class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Bird.java b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Bird.java
index e672bc7026fe..4fe1c8df7963 100644
--- a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Bird.java
+++ b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Bird.java
@@ -128,10 +128,7 @@ public class Bird {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Category.java b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Category.java
index 5935a97f9090..423a20c0aadd 100644
--- a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Category.java
@@ -128,10 +128,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/DataQuery.java b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/DataQuery.java
index 456fe27542e9..21ccce418aff 100644
--- a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/DataQuery.java
+++ b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/DataQuery.java
@@ -180,10 +180,7 @@ public class DataQuery extends Query {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/DefaultValue.java b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/DefaultValue.java
index 2416a7da5ac0..50f37fad618c 100644
--- a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/DefaultValue.java
+++ b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/DefaultValue.java
@@ -464,10 +464,7 @@ public class DefaultValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
index 58d8ff8703ef..ec3b0ef8ed08 100644
--- a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
+++ b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
@@ -163,10 +163,7 @@ public class NumberPropertiesOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Pet.java
index b385bd3e234e..1fd3c4eb2ce0 100644
--- a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Pet.java
@@ -314,10 +314,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Query.java b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Query.java
index 53f17a978e74..6db71ab545fc 100644
--- a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Query.java
+++ b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Query.java
@@ -176,10 +176,7 @@ public class Query {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Tag.java
index d242e13eec99..9ae856061d84 100644
--- a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Tag.java
@@ -128,10 +128,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
index 191683b5097c..021f1dfa5673 100644
--- a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
+++ b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
@@ -97,10 +97,7 @@ public class TestFormObjectMultipartRequestMarker {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
index 7d9de9a62229..b6497b52ca91 100644
--- a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
+++ b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
@@ -193,10 +193,7 @@ public class TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
index 6d300168a478..0ad103730e59 100644
--- a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
+++ b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
@@ -108,10 +108,7 @@ public class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Bird.java b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Bird.java
index 90781a485d6f..2618abee79c1 100644
--- a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Bird.java
+++ b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Bird.java
@@ -127,10 +127,7 @@ public class Bird {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Category.java b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Category.java
index 4b395f279418..a5f9942bc9c7 100644
--- a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Category.java
@@ -127,10 +127,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/DataQuery.java b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/DataQuery.java
index 99bf42ead58e..c18bf279a66f 100644
--- a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/DataQuery.java
+++ b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/DataQuery.java
@@ -179,10 +179,7 @@ public class DataQuery extends Query {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/DefaultValue.java b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/DefaultValue.java
index 6b36ebe3fafc..4500eea84306 100644
--- a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/DefaultValue.java
+++ b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/DefaultValue.java
@@ -463,10 +463,7 @@ public class DefaultValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
index 8518a6dd747e..96c8a83ae4ad 100644
--- a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
+++ b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
@@ -162,10 +162,7 @@ public class NumberPropertiesOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Pet.java
index ff3d623bedc4..42bab9c26914 100644
--- a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Pet.java
@@ -313,10 +313,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Query.java b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Query.java
index 3b096dc6c643..7ba492211abe 100644
--- a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Query.java
+++ b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Query.java
@@ -175,10 +175,7 @@ public class Query {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Tag.java
index 7de946972eba..d4cd69818e68 100644
--- a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Tag.java
@@ -127,10 +127,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
index fd8c78019331..2350076c829d 100644
--- a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
+++ b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
@@ -96,10 +96,7 @@ public class TestFormObjectMultipartRequestMarker {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
index 73813e24b69f..7a350ec333a3 100644
--- a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
+++ b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
@@ -192,10 +192,7 @@ public class TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
index a7b161a0aca6..df79925057a7 100644
--- a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
+++ b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
@@ -107,10 +107,7 @@ public class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Bird.java b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Bird.java
index 6ef437333535..70ec2421ab22 100644
--- a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Bird.java
+++ b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Bird.java
@@ -128,10 +128,7 @@ public class Bird {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Category.java b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Category.java
index 1fb6ac29f529..d92c43090bd2 100644
--- a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Category.java
@@ -128,10 +128,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/DataQuery.java b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/DataQuery.java
index 1e1028d3e8c8..9026eee5a417 100644
--- a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/DataQuery.java
+++ b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/DataQuery.java
@@ -180,10 +180,7 @@ public class DataQuery extends Query {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/DefaultValue.java b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/DefaultValue.java
index 762af5cf7ffc..136abc683b59 100644
--- a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/DefaultValue.java
+++ b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/DefaultValue.java
@@ -464,10 +464,7 @@ public class DefaultValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
index 6324a538650d..e9d4c7b94eb2 100644
--- a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
+++ b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/NumberPropertiesOnly.java
@@ -163,10 +163,7 @@ public class NumberPropertiesOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Pet.java
index 1d8a1f9142c2..17cadcba2e56 100644
--- a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Pet.java
@@ -314,10 +314,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Query.java b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Query.java
index f35926897f01..b803d69d1960 100644
--- a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Query.java
+++ b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Query.java
@@ -176,10 +176,7 @@ public class Query {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Tag.java
index 5e85cc50af09..58f2e8482eec 100644
--- a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/Tag.java
@@ -128,10 +128,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
index 0dd142673623..8cfdd451c3a0 100644
--- a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
+++ b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/TestFormObjectMultipartRequestMarker.java
@@ -97,10 +97,7 @@ public class TestFormObjectMultipartRequestMarker {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
index 27cbc2d1634c..293e180850dc 100644
--- a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
+++ b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.java
@@ -193,10 +193,7 @@ public class TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
index 2081d69499ed..b75900fabe1a 100644
--- a/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
+++ b/samples/client/echo_api/java/resttemplate/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
@@ -108,10 +108,7 @@ public class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/jersey2-oneOf-Mixed/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/others/java/jersey2-oneOf-Mixed/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 53609b09d94d..74a4f4a29783 100644
--- a/samples/client/others/java/jersey2-oneOf-Mixed/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/others/java/jersey2-oneOf-Mixed/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -107,10 +107,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/others/java/jersey2-oneOf-duplicates/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/others/java/jersey2-oneOf-duplicates/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 53609b09d94d..74a4f4a29783 100644
--- a/samples/client/others/java/jersey2-oneOf-duplicates/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/others/java/jersey2-oneOf-duplicates/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -107,10 +107,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/others/java/okhttp-gson-oneOf-array/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/others/java/okhttp-gson-oneOf-array/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 67618f7298dd..021c73e55a03 100644
--- a/samples/client/others/java/okhttp-gson-oneOf-array/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/others/java/okhttp-gson-oneOf-array/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -104,10 +104,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/others/java/okhttp-gson-oneOf-array/src/main/java/org/openapitools/client/model/OneOf1.java b/samples/client/others/java/okhttp-gson-oneOf-array/src/main/java/org/openapitools/client/model/OneOf1.java
index fdcb9a1cc74b..d26115234f28 100644
--- a/samples/client/others/java/okhttp-gson-oneOf-array/src/main/java/org/openapitools/client/model/OneOf1.java
+++ b/samples/client/others/java/okhttp-gson-oneOf-array/src/main/java/org/openapitools/client/model/OneOf1.java
@@ -112,10 +112,7 @@ public class OneOf1 {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index c3b48a113fd6..fd0a43eec20a 100644
--- a/samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -104,10 +104,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/others/java/okhttp-gson-streaming/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/others/java/okhttp-gson-streaming/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index e49b64bdd914..4507596bea18 100644
--- a/samples/client/others/java/okhttp-gson-streaming/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/others/java/okhttp-gson-streaming/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -104,10 +104,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/others/java/okhttp-gson-streaming/src/main/java/org/openapitools/client/model/SomeObj.java b/samples/client/others/java/okhttp-gson-streaming/src/main/java/org/openapitools/client/model/SomeObj.java
index 477d554acf52..3db73bf0e5a7 100644
--- a/samples/client/others/java/okhttp-gson-streaming/src/main/java/org/openapitools/client/model/SomeObj.java
+++ b/samples/client/others/java/okhttp-gson-streaming/src/main/java/org/openapitools/client/model/SomeObj.java
@@ -266,10 +266,7 @@ public class SomeObj implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/others/java/restclient-enum-in-multipart/src/main/java/org/openapitools/client/model/InlineObject.java b/samples/client/others/java/restclient-enum-in-multipart/src/main/java/org/openapitools/client/model/InlineObject.java
index ad27d177ffff..969d48898b6f 100644
--- a/samples/client/others/java/restclient-enum-in-multipart/src/main/java/org/openapitools/client/model/InlineObject.java
+++ b/samples/client/others/java/restclient-enum-in-multipart/src/main/java/org/openapitools/client/model/InlineObject.java
@@ -98,10 +98,7 @@ public class InlineObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Addressable.java b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Addressable.java
index 130610acfa8a..7a1b26f65349 100644
--- a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Addressable.java
+++ b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Addressable.java
@@ -131,10 +131,7 @@ public final class Addressable implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Apple.java b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Apple.java
index 7a3dcb3df115..a4972c07edf8 100644
--- a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Apple.java
+++ b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Apple.java
@@ -134,10 +134,7 @@ public final class Apple implements Serializable, Fruit {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Banana.java b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Banana.java
index 49ea8db322b0..21852d13f5a0 100644
--- a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Banana.java
+++ b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Banana.java
@@ -134,10 +134,7 @@ public final class Banana implements Serializable, Fruit {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Bar.java b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Bar.java
index b95485dfdce3..40230681cccc 100644
--- a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Bar.java
+++ b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Bar.java
@@ -233,10 +233,7 @@ public final class Bar extends Entity implements Serializable, BarRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/BarCreate.java b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/BarCreate.java
index 8276bc9bc711..a957d30b732b 100644
--- a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/BarCreate.java
+++ b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/BarCreate.java
@@ -208,10 +208,7 @@ public final class BarCreate extends Entity implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/BarRef.java b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/BarRef.java
index 8ed479b33013..069fe9fc0267 100644
--- a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/BarRef.java
+++ b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/BarRef.java
@@ -109,10 +109,7 @@ public final class BarRef extends EntityRef implements Serializable, BarRefOrVal
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Cat.java
index 3165f3ad5335..549b102943a1 100644
--- a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Cat.java
@@ -99,10 +99,7 @@ public final class Cat implements Serializable, Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Dog.java
index 110553985381..a242818ebd24 100644
--- a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Dog.java
@@ -99,10 +99,7 @@ public final class Dog implements Serializable, Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Entity.java b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Entity.java
index 2ae7521ba1b7..705279289c6a 100644
--- a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Entity.java
+++ b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Entity.java
@@ -244,10 +244,7 @@ public class Entity implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/EntityRef.java b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/EntityRef.java
index 690e269c98f4..b2ded98af8a7 100644
--- a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/EntityRef.java
+++ b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/EntityRef.java
@@ -304,10 +304,7 @@ public class EntityRef implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Extensible.java b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Extensible.java
index 482ea86c2b67..e02d502f3b84 100644
--- a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Extensible.java
+++ b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Extensible.java
@@ -163,10 +163,7 @@ public final class Extensible implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Foo.java
index 47789a9580bd..e8b0a7a9c4c9 100644
--- a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Foo.java
@@ -174,10 +174,7 @@ public final class Foo extends Entity implements Serializable, FooRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/FooRef.java b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/FooRef.java
index a8ce77e8b762..bb7875995062 100644
--- a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/FooRef.java
+++ b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/FooRef.java
@@ -142,10 +142,7 @@ public final class FooRef extends EntityRef implements Serializable, FooRefOrVal
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Pasta.java b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Pasta.java
index 43b38a33e73e..a0e9e520100e 100644
--- a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Pasta.java
+++ b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Pasta.java
@@ -142,10 +142,7 @@ public final class Pasta extends Entity implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Pizza.java b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Pizza.java
index 8e2790920e1f..7097099b8a48 100644
--- a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Pizza.java
+++ b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/Pizza.java
@@ -146,10 +146,7 @@ public class Pizza extends Entity implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/PizzaSpeziale.java b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/PizzaSpeziale.java
index 39fcf82bfd7a..cb2a9c0da379 100644
--- a/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/PizzaSpeziale.java
+++ b/samples/client/others/java/restclient-sealedInterface/src/main/java/org/openapitools/client/model/PizzaSpeziale.java
@@ -143,10 +143,7 @@ public final class PizzaSpeziale extends Pizza implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Addressable.java b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Addressable.java
index fde66b47e7e8..b73e493077e6 100644
--- a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Addressable.java
+++ b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Addressable.java
@@ -127,10 +127,7 @@ public class Addressable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Apple.java b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Apple.java
index c33232f55a83..4f837950bf3a 100644
--- a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Apple.java
+++ b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Apple.java
@@ -130,10 +130,7 @@ public final class Apple implements Fruit {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Banana.java b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Banana.java
index d42d5b6a55c3..8b81a7e2c222 100644
--- a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Banana.java
+++ b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Banana.java
@@ -130,10 +130,7 @@ public final class Banana implements Fruit {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Bar.java b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Bar.java
index 988d9d69dbc8..11d48b4a4970 100644
--- a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Bar.java
+++ b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Bar.java
@@ -205,10 +205,7 @@ public final class Bar extends Entity implements BarRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/BarCreate.java b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/BarCreate.java
index 278dc8b2c97a..297d2e40e0c1 100644
--- a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/BarCreate.java
+++ b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/BarCreate.java
@@ -174,10 +174,7 @@ public class BarCreate extends Entity {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/BarRef.java b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/BarRef.java
index 5658a890bcfd..ceba441b32eb 100644
--- a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/BarRef.java
+++ b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/BarRef.java
@@ -75,10 +75,7 @@ public final class BarRef extends EntityRef implements BarRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Cat.java
index 4aef4fde20f0..0bfc8c0396c4 100644
--- a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Cat.java
@@ -95,10 +95,7 @@ public final class Cat implements Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Dog.java
index c33713977042..da362a2cd69e 100644
--- a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Dog.java
@@ -95,10 +95,7 @@ public final class Dog implements Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Entity.java b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Entity.java
index c5ffe3417ef7..5d5404bc9478 100644
--- a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Entity.java
+++ b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Entity.java
@@ -240,10 +240,7 @@ public class Entity {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/EntityRef.java b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/EntityRef.java
index bd29a73ded9e..e3f5ed591ea7 100644
--- a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/EntityRef.java
+++ b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/EntityRef.java
@@ -300,10 +300,7 @@ public class EntityRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Extensible.java b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Extensible.java
index ded728b54f5b..9848fa0459fa 100644
--- a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Extensible.java
+++ b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Extensible.java
@@ -159,10 +159,7 @@ public class Extensible {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Foo.java
index bed3b965b7c2..4a02e280d3e5 100644
--- a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Foo.java
@@ -140,10 +140,7 @@ public final class Foo extends Entity implements FooRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/FooRef.java b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/FooRef.java
index f1a74e252214..6603ccfb882b 100644
--- a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/FooRef.java
+++ b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/FooRef.java
@@ -108,10 +108,7 @@ public final class FooRef extends EntityRef implements FooRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Pasta.java b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Pasta.java
index 8edf61ec0e1d..59c80bd6a535 100644
--- a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Pasta.java
+++ b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Pasta.java
@@ -108,10 +108,7 @@ public class Pasta extends Entity {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Pizza.java b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Pizza.java
index 9912653b5da3..8d129725a83f 100644
--- a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Pizza.java
+++ b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/Pizza.java
@@ -112,10 +112,7 @@ public class Pizza extends Entity {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/PizzaSpeziale.java b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/PizzaSpeziale.java
index b44676fb328f..bd5e2d2a07fc 100644
--- a/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/PizzaSpeziale.java
+++ b/samples/client/others/java/webclient-sealedInterface/src/main/java/org/openapitools/client/model/PizzaSpeziale.java
@@ -109,10 +109,7 @@ public class PizzaSpeziale extends Pizza {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Addressable.java b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Addressable.java
index fde66b47e7e8..b73e493077e6 100644
--- a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Addressable.java
+++ b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Addressable.java
@@ -127,10 +127,7 @@ public class Addressable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Apple.java b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Apple.java
index 4d3660e09524..3b5f6160e63d 100644
--- a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Apple.java
+++ b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Apple.java
@@ -130,10 +130,7 @@ public final class Apple implements Fruit {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Banana.java b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Banana.java
index b0720bb52c09..8acfd9c7c6d8 100644
--- a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Banana.java
+++ b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Banana.java
@@ -130,10 +130,7 @@ public final class Banana implements Fruit {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Bar.java b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Bar.java
index 5e0705cb29dc..b90d7495eb5b 100644
--- a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Bar.java
+++ b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Bar.java
@@ -229,10 +229,7 @@ public final class Bar extends Entity implements BarRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/BarCreate.java b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/BarCreate.java
index 3a4a3d335bc3..4d92e83cd6dd 100644
--- a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/BarCreate.java
+++ b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/BarCreate.java
@@ -204,10 +204,7 @@ public class BarCreate extends Entity {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/BarRef.java b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/BarRef.java
index 7c07d8a630bd..a70117bbba9b 100644
--- a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/BarRef.java
+++ b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/BarRef.java
@@ -105,10 +105,7 @@ public final class BarRef extends EntityRef implements BarRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Cat.java
index 4aef4fde20f0..0bfc8c0396c4 100644
--- a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Cat.java
@@ -95,10 +95,7 @@ public final class Cat implements Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Dog.java
index c33713977042..da362a2cd69e 100644
--- a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Dog.java
@@ -95,10 +95,7 @@ public final class Dog implements Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Entity.java b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Entity.java
index c5ffe3417ef7..5d5404bc9478 100644
--- a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Entity.java
+++ b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Entity.java
@@ -240,10 +240,7 @@ public class Entity {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/EntityRef.java b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/EntityRef.java
index bd29a73ded9e..e3f5ed591ea7 100644
--- a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/EntityRef.java
+++ b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/EntityRef.java
@@ -300,10 +300,7 @@ public class EntityRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Extensible.java b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Extensible.java
index ded728b54f5b..9848fa0459fa 100644
--- a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Extensible.java
+++ b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Extensible.java
@@ -159,10 +159,7 @@ public class Extensible {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Foo.java
index 89e147f0d2b4..a0d103ff03f4 100644
--- a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Foo.java
@@ -170,10 +170,7 @@ public final class Foo extends Entity implements FooRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/FooRef.java b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/FooRef.java
index 10c23499f85f..eea36352c012 100644
--- a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/FooRef.java
+++ b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/FooRef.java
@@ -138,10 +138,7 @@ public final class FooRef extends EntityRef implements FooRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Pasta.java b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Pasta.java
index 2939a6b37468..012d865e0ead 100644
--- a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Pasta.java
+++ b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Pasta.java
@@ -138,10 +138,7 @@ public class Pasta extends Entity {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Pizza.java b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Pizza.java
index 347909a02cad..baa193429680 100644
--- a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Pizza.java
+++ b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/Pizza.java
@@ -142,10 +142,7 @@ public class Pizza extends Entity {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/PizzaSpeziale.java b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/PizzaSpeziale.java
index 44e761bc8644..47a2cc20d8df 100644
--- a/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/PizzaSpeziale.java
+++ b/samples/client/others/java/webclient-sealedInterface_3_1/src/main/java/org/openapitools/client/model/PizzaSpeziale.java
@@ -139,10 +139,7 @@ public class PizzaSpeziale extends Pizza {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 6aa9a4a7216e..07ec3901877e 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -99,10 +99,7 @@ public class AdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 72c024a8bdbd..5231c910810f 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -88,10 +88,7 @@ public class AllOfWithSingleRef  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Animal.java
index f31881bf0a4b..ddafd3b26fef 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Animal.java
@@ -90,10 +90,7 @@ public class Animal  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index f44aab22fbe9..6a4047427787 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -73,10 +73,7 @@ public class ArrayOfArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index c3acdb4bb5de..645d56ddd1ed 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -73,10 +73,7 @@ public class ArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ArrayTest.java
index 02a1a023d9d1..e24cf2deeb04 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -129,10 +129,7 @@ public class ArrayTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Capitalization.java
index 01243513aa76..d873391e02ef 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -182,10 +182,7 @@ public class Capitalization  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Cat.java
index b4c7b76144e2..551827b1cfcb 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Cat.java
@@ -68,10 +68,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Category.java
index b199a65de2a2..bffedbdb8c50 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Category.java
@@ -87,10 +87,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index cbbf037841f6..573b02d50a3d 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -69,10 +69,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ClassModel.java
index acf016ffed8e..21ce2c90fcc6 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -67,10 +67,7 @@ public class ClassModel  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Client.java
index 8c38733897f6..a31495e092c3 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Client.java
@@ -64,10 +64,7 @@ public class Client  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 2eb2c927f9e1..69d9f52036e4 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -64,10 +64,7 @@ public class DeprecatedObject  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Dog.java
index c53348e9f03b..b3df56b12762 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Dog.java
@@ -68,10 +68,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/EnumArrays.java
index 52cf662eb13f..d58536bf1489 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -137,10 +137,7 @@ public enum ArrayEnumEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/EnumTest.java
index bb19c7b14e3f..e388b30ae9b7 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -316,10 +316,7 @@ public enum EnumNumberEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index 0a7638fd26f2..d2483b804151 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -95,10 +95,7 @@ public class FakeBigDecimalMap200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index f88e6bf18ba8..42388dbbbedb 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -96,10 +96,7 @@ public class FileSchemaTestClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Foo.java
index 10d859a1407b..119bb33b6d75 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Foo.java
@@ -64,10 +64,7 @@ public class Foo  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index fe9631dd0fe0..1beb903ba5c6 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -65,10 +65,7 @@ public class FooGetDefaultResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/FormatTest.java
index 0d7d0eb80c10..8f356333309a 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -430,10 +430,7 @@ public class FormatTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index b070ee9c0301..114aa0204312 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -65,10 +65,7 @@ public class HasOnlyReadOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index cda36c1f2ef8..39b3f68c8458 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -70,10 +70,7 @@ public class HealthCheckResult  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/MapTest.java
index 6142358f5cd4..6ea1e1f1b3e3 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/MapTest.java
@@ -176,10 +176,7 @@ public enum InnerEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 845d07024ac4..4e335c8157f1 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -120,10 +120,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Model200Response.java
index 069c870eb8c0..c45c73273585 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -90,10 +90,7 @@ public class Model200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index ba8aa80736cb..1d738b401c7b 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -110,10 +110,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ModelFile.java
index 303abbffe233..62ba1ca8f115 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -70,10 +70,7 @@ public class ModelFile  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ModelList.java
index 228e3d431560..2fe5030f40da 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ModelList.java
@@ -64,10 +64,7 @@ public class ModelList  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ModelReturn.java
index c96a4fdeb8cd..4f170a7ee5a4 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -67,10 +67,7 @@ public class ModelReturn  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Name.java
index 30e3bafc1fea..fbe71a471e0c 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Name.java
@@ -114,10 +114,7 @@ public class Name  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/NullableClass.java
index b211fc399bce..46e639aaf8c8 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -358,10 +358,7 @@ public class NullableClass extends HashMap<String, Object> {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/NumberOnly.java
index de9e6be8f033..9adcd56a4af1 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -65,10 +65,7 @@ public class NumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index bca25c900ade..f049525b38ec 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -149,10 +149,7 @@ public class ObjectWithDeprecatedFields  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Order.java
index eb935f23a415..921de8fa9748 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Order.java
@@ -204,10 +204,7 @@ public enum StatusEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/OuterComposite.java
index 82f1783f9032..c20b3cbcc1ff 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -111,10 +111,7 @@ public class OuterComposite  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 4d2b828f225e..222f2802decc 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -65,10 +65,7 @@ public class OuterObjectWithEnumProperty  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index 4323bd678396..27409bbe2e7c 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -114,10 +114,7 @@ public enum TypeEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Pet.java
index b9ca662b517b..5e5ca4dce1eb 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Pet.java
@@ -222,10 +222,7 @@ public enum StatusEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 56d00d4e30b9..6c9e1d460df9 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -76,10 +76,7 @@ public class ReadOnlyFirst  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/SpecialModelName.java
index ef0d6d0d1245..24f242828ebe 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -64,10 +64,7 @@ public class SpecialModelName  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Tag.java
index b2e3d046e089..da67b13f576a 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/Tag.java
@@ -87,10 +87,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index ec87253bc19d..b6ed44150c7f 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -66,10 +66,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/User.java
index 35946e1c21aa..4ec14b22a173 100644
--- a/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java-helidon-client/v3/mp/src/main/java/org/openapitools/client/model/User.java
@@ -228,10 +228,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 6aa9a4a7216e..07ec3901877e 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -99,10 +99,7 @@ public class AdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 72c024a8bdbd..5231c910810f 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -88,10 +88,7 @@ public class AllOfWithSingleRef  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Animal.java
index f31881bf0a4b..ddafd3b26fef 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Animal.java
@@ -90,10 +90,7 @@ public class Animal  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index f44aab22fbe9..6a4047427787 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -73,10 +73,7 @@ public class ArrayOfArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index c3acdb4bb5de..645d56ddd1ed 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -73,10 +73,7 @@ public class ArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ArrayTest.java
index 02a1a023d9d1..e24cf2deeb04 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -129,10 +129,7 @@ public class ArrayTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Capitalization.java
index 01243513aa76..d873391e02ef 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -182,10 +182,7 @@ public class Capitalization  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Cat.java
index b4c7b76144e2..551827b1cfcb 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Cat.java
@@ -68,10 +68,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Category.java
index b199a65de2a2..bffedbdb8c50 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Category.java
@@ -87,10 +87,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index cbbf037841f6..573b02d50a3d 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -69,10 +69,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ClassModel.java
index acf016ffed8e..21ce2c90fcc6 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -67,10 +67,7 @@ public class ClassModel  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Client.java
index 8c38733897f6..a31495e092c3 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Client.java
@@ -64,10 +64,7 @@ public class Client  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 2eb2c927f9e1..69d9f52036e4 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -64,10 +64,7 @@ public class DeprecatedObject  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Dog.java
index c53348e9f03b..b3df56b12762 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Dog.java
@@ -68,10 +68,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/EnumArrays.java
index 52cf662eb13f..d58536bf1489 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -137,10 +137,7 @@ public enum ArrayEnumEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/EnumTest.java
index bb19c7b14e3f..e388b30ae9b7 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -316,10 +316,7 @@ public enum EnumNumberEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index 0a7638fd26f2..d2483b804151 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -95,10 +95,7 @@ public class FakeBigDecimalMap200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index f88e6bf18ba8..42388dbbbedb 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -96,10 +96,7 @@ public class FileSchemaTestClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Foo.java
index 10d859a1407b..119bb33b6d75 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Foo.java
@@ -64,10 +64,7 @@ public class Foo  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index fe9631dd0fe0..1beb903ba5c6 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -65,10 +65,7 @@ public class FooGetDefaultResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/FormatTest.java
index 0d7d0eb80c10..8f356333309a 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -430,10 +430,7 @@ public class FormatTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index b070ee9c0301..114aa0204312 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -65,10 +65,7 @@ public class HasOnlyReadOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index cda36c1f2ef8..39b3f68c8458 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -70,10 +70,7 @@ public class HealthCheckResult  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/MapTest.java
index 6142358f5cd4..6ea1e1f1b3e3 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/MapTest.java
@@ -176,10 +176,7 @@ public enum InnerEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 845d07024ac4..4e335c8157f1 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -120,10 +120,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Model200Response.java
index 069c870eb8c0..c45c73273585 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -90,10 +90,7 @@ public class Model200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index ba8aa80736cb..1d738b401c7b 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -110,10 +110,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ModelFile.java
index 303abbffe233..62ba1ca8f115 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -70,10 +70,7 @@ public class ModelFile  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ModelList.java
index 228e3d431560..2fe5030f40da 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ModelList.java
@@ -64,10 +64,7 @@ public class ModelList  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ModelReturn.java
index c96a4fdeb8cd..4f170a7ee5a4 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -67,10 +67,7 @@ public class ModelReturn  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Name.java
index 30e3bafc1fea..fbe71a471e0c 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Name.java
@@ -114,10 +114,7 @@ public class Name  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/NullableClass.java
index b211fc399bce..46e639aaf8c8 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -358,10 +358,7 @@ public class NullableClass extends HashMap<String, Object> {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/NumberOnly.java
index de9e6be8f033..9adcd56a4af1 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -65,10 +65,7 @@ public class NumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index bca25c900ade..f049525b38ec 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -149,10 +149,7 @@ public class ObjectWithDeprecatedFields  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Order.java
index eb935f23a415..921de8fa9748 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Order.java
@@ -204,10 +204,7 @@ public enum StatusEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/OuterComposite.java
index 82f1783f9032..c20b3cbcc1ff 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -111,10 +111,7 @@ public class OuterComposite  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 4d2b828f225e..222f2802decc 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -65,10 +65,7 @@ public class OuterObjectWithEnumProperty  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index 4323bd678396..27409bbe2e7c 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -114,10 +114,7 @@ public enum TypeEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Pet.java
index b9ca662b517b..5e5ca4dce1eb 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Pet.java
@@ -222,10 +222,7 @@ public enum StatusEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 56d00d4e30b9..6c9e1d460df9 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -76,10 +76,7 @@ public class ReadOnlyFirst  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/SpecialModelName.java
index ef0d6d0d1245..24f242828ebe 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -64,10 +64,7 @@ public class SpecialModelName  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Tag.java
index b2e3d046e089..da67b13f576a 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/Tag.java
@@ -87,10 +87,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index ec87253bc19d..b6ed44150c7f 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -66,10 +66,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/User.java
index 35946e1c21aa..4ec14b22a173 100644
--- a/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java-helidon-client/v3/se/src/main/java/org/openapitools/client/model/User.java
@@ -228,10 +228,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 6aa9a4a7216e..07ec3901877e 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -99,10 +99,7 @@ public class AdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 72c024a8bdbd..5231c910810f 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -88,10 +88,7 @@ public class AllOfWithSingleRef  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Animal.java
index f31881bf0a4b..ddafd3b26fef 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Animal.java
@@ -90,10 +90,7 @@ public class Animal  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index f44aab22fbe9..6a4047427787 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -73,10 +73,7 @@ public class ArrayOfArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index c3acdb4bb5de..645d56ddd1ed 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -73,10 +73,7 @@ public class ArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ArrayTest.java
index 02a1a023d9d1..e24cf2deeb04 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -129,10 +129,7 @@ public class ArrayTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Capitalization.java
index 01243513aa76..d873391e02ef 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -182,10 +182,7 @@ public class Capitalization  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Cat.java
index b4c7b76144e2..551827b1cfcb 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Cat.java
@@ -68,10 +68,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Category.java
index b199a65de2a2..bffedbdb8c50 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Category.java
@@ -87,10 +87,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index cbbf037841f6..573b02d50a3d 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -69,10 +69,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ClassModel.java
index acf016ffed8e..21ce2c90fcc6 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -67,10 +67,7 @@ public class ClassModel  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Client.java
index 8c38733897f6..a31495e092c3 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Client.java
@@ -64,10 +64,7 @@ public class Client  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 2eb2c927f9e1..69d9f52036e4 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -64,10 +64,7 @@ public class DeprecatedObject  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Dog.java
index c53348e9f03b..b3df56b12762 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Dog.java
@@ -68,10 +68,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/EnumArrays.java
index 52cf662eb13f..d58536bf1489 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -137,10 +137,7 @@ public enum ArrayEnumEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/EnumTest.java
index bb19c7b14e3f..e388b30ae9b7 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -316,10 +316,7 @@ public enum EnumNumberEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index 0a7638fd26f2..d2483b804151 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -95,10 +95,7 @@ public class FakeBigDecimalMap200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index f88e6bf18ba8..42388dbbbedb 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -96,10 +96,7 @@ public class FileSchemaTestClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Foo.java
index 10d859a1407b..119bb33b6d75 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Foo.java
@@ -64,10 +64,7 @@ public class Foo  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index fe9631dd0fe0..1beb903ba5c6 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -65,10 +65,7 @@ public class FooGetDefaultResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/FormatTest.java
index 0d7d0eb80c10..8f356333309a 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -430,10 +430,7 @@ public class FormatTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index b070ee9c0301..114aa0204312 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -65,10 +65,7 @@ public class HasOnlyReadOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index cda36c1f2ef8..39b3f68c8458 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -70,10 +70,7 @@ public class HealthCheckResult  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/MapTest.java
index 6142358f5cd4..6ea1e1f1b3e3 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/MapTest.java
@@ -176,10 +176,7 @@ public enum InnerEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 845d07024ac4..4e335c8157f1 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -120,10 +120,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Model200Response.java
index 069c870eb8c0..c45c73273585 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -90,10 +90,7 @@ public class Model200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index ba8aa80736cb..1d738b401c7b 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -110,10 +110,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ModelFile.java
index 303abbffe233..62ba1ca8f115 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -70,10 +70,7 @@ public class ModelFile  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ModelList.java
index 228e3d431560..2fe5030f40da 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ModelList.java
@@ -64,10 +64,7 @@ public class ModelList  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ModelReturn.java
index c96a4fdeb8cd..4f170a7ee5a4 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -67,10 +67,7 @@ public class ModelReturn  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Name.java
index 30e3bafc1fea..fbe71a471e0c 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Name.java
@@ -114,10 +114,7 @@ public class Name  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/NullableClass.java
index b211fc399bce..46e639aaf8c8 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -358,10 +358,7 @@ public class NullableClass extends HashMap<String, Object> {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/NumberOnly.java
index de9e6be8f033..9adcd56a4af1 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -65,10 +65,7 @@ public class NumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index bca25c900ade..f049525b38ec 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -149,10 +149,7 @@ public class ObjectWithDeprecatedFields  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Order.java
index eb935f23a415..921de8fa9748 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Order.java
@@ -204,10 +204,7 @@ public enum StatusEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/OuterComposite.java
index 82f1783f9032..c20b3cbcc1ff 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -111,10 +111,7 @@ public class OuterComposite  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 4d2b828f225e..222f2802decc 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -65,10 +65,7 @@ public class OuterObjectWithEnumProperty  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index 4323bd678396..27409bbe2e7c 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -114,10 +114,7 @@ public enum TypeEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Pet.java
index b9ca662b517b..5e5ca4dce1eb 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Pet.java
@@ -222,10 +222,7 @@ public enum StatusEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 56d00d4e30b9..6c9e1d460df9 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -76,10 +76,7 @@ public class ReadOnlyFirst  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/SpecialModelName.java
index ef0d6d0d1245..24f242828ebe 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -64,10 +64,7 @@ public class SpecialModelName  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Tag.java
index b2e3d046e089..da67b13f576a 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/Tag.java
@@ -87,10 +87,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index ec87253bc19d..b6ed44150c7f 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -66,10 +66,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/User.java
index 35946e1c21aa..4ec14b22a173 100644
--- a/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java-helidon-client/v4/mp/src/main/java/org/openapitools/client/model/User.java
@@ -228,10 +228,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 6aa9a4a7216e..07ec3901877e 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -99,10 +99,7 @@ public class AdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 72c024a8bdbd..5231c910810f 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -88,10 +88,7 @@ public class AllOfWithSingleRef  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Animal.java
index f31881bf0a4b..ddafd3b26fef 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Animal.java
@@ -90,10 +90,7 @@ public class Animal  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index f44aab22fbe9..6a4047427787 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -73,10 +73,7 @@ public class ArrayOfArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index c3acdb4bb5de..645d56ddd1ed 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -73,10 +73,7 @@ public class ArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ArrayTest.java
index 02a1a023d9d1..e24cf2deeb04 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -129,10 +129,7 @@ public class ArrayTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Capitalization.java
index 01243513aa76..d873391e02ef 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -182,10 +182,7 @@ public class Capitalization  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Cat.java
index b4c7b76144e2..551827b1cfcb 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Cat.java
@@ -68,10 +68,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Category.java
index b199a65de2a2..bffedbdb8c50 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Category.java
@@ -87,10 +87,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index cbbf037841f6..573b02d50a3d 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -69,10 +69,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ClassModel.java
index acf016ffed8e..21ce2c90fcc6 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -67,10 +67,7 @@ public class ClassModel  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Client.java
index 8c38733897f6..a31495e092c3 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Client.java
@@ -64,10 +64,7 @@ public class Client  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 2eb2c927f9e1..69d9f52036e4 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -64,10 +64,7 @@ public class DeprecatedObject  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Dog.java
index c53348e9f03b..b3df56b12762 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Dog.java
@@ -68,10 +68,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/EnumArrays.java
index 52cf662eb13f..d58536bf1489 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -137,10 +137,7 @@ public enum ArrayEnumEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/EnumTest.java
index bb19c7b14e3f..e388b30ae9b7 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -316,10 +316,7 @@ public enum EnumNumberEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index 0a7638fd26f2..d2483b804151 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -95,10 +95,7 @@ public class FakeBigDecimalMap200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index f88e6bf18ba8..42388dbbbedb 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -96,10 +96,7 @@ public class FileSchemaTestClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Foo.java
index 10d859a1407b..119bb33b6d75 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Foo.java
@@ -64,10 +64,7 @@ public class Foo  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index fe9631dd0fe0..1beb903ba5c6 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -65,10 +65,7 @@ public class FooGetDefaultResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/FormatTest.java
index 0d7d0eb80c10..8f356333309a 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -430,10 +430,7 @@ public class FormatTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index b070ee9c0301..114aa0204312 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -65,10 +65,7 @@ public class HasOnlyReadOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index cda36c1f2ef8..39b3f68c8458 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -70,10 +70,7 @@ public class HealthCheckResult  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/MapTest.java
index 6142358f5cd4..6ea1e1f1b3e3 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/MapTest.java
@@ -176,10 +176,7 @@ public enum InnerEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 845d07024ac4..4e335c8157f1 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -120,10 +120,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Model200Response.java
index 069c870eb8c0..c45c73273585 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -90,10 +90,7 @@ public class Model200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index ba8aa80736cb..1d738b401c7b 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -110,10 +110,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ModelFile.java
index 303abbffe233..62ba1ca8f115 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -70,10 +70,7 @@ public class ModelFile  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ModelList.java
index 228e3d431560..2fe5030f40da 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ModelList.java
@@ -64,10 +64,7 @@ public class ModelList  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ModelReturn.java
index c96a4fdeb8cd..4f170a7ee5a4 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -67,10 +67,7 @@ public class ModelReturn  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Name.java
index 30e3bafc1fea..fbe71a471e0c 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Name.java
@@ -114,10 +114,7 @@ public class Name  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/NullableClass.java
index b211fc399bce..46e639aaf8c8 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -358,10 +358,7 @@ public class NullableClass extends HashMap<String, Object> {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/NumberOnly.java
index de9e6be8f033..9adcd56a4af1 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -65,10 +65,7 @@ public class NumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index bca25c900ade..f049525b38ec 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -149,10 +149,7 @@ public class ObjectWithDeprecatedFields  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Order.java
index eb935f23a415..921de8fa9748 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Order.java
@@ -204,10 +204,7 @@ public enum StatusEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/OuterComposite.java
index 82f1783f9032..c20b3cbcc1ff 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -111,10 +111,7 @@ public class OuterComposite  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 4d2b828f225e..222f2802decc 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -65,10 +65,7 @@ public class OuterObjectWithEnumProperty  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index 4323bd678396..27409bbe2e7c 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -114,10 +114,7 @@ public enum TypeEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Pet.java
index b9ca662b517b..5e5ca4dce1eb 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Pet.java
@@ -222,10 +222,7 @@ public enum StatusEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 56d00d4e30b9..6c9e1d460df9 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -76,10 +76,7 @@ public class ReadOnlyFirst  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/SpecialModelName.java
index ef0d6d0d1245..24f242828ebe 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -64,10 +64,7 @@ public class SpecialModelName  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Tag.java
index b2e3d046e089..da67b13f576a 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/Tag.java
@@ -87,10 +87,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index ec87253bc19d..b6ed44150c7f 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -66,10 +66,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/User.java
index 35946e1c21aa..4ec14b22a173 100644
--- a/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java-helidon-client/v4/se/src/main/java/org/openapitools/client/model/User.java
@@ -228,10 +228,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index bb4ee5837877..9f93419ef24c 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -94,10 +94,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object> {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index 3c488c910ee3..5bb3482c137e 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -95,10 +95,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List> {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 4c12c963a741..c0ca4ad0fa1b 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -94,10 +94,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean> {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index b81d88b898ad..e8ae76460b92 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -437,10 +437,7 @@ public class AdditionalPropertiesClass {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index d3a620dda009..337ca0a5bddb 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -94,10 +94,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer> {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index 5de1fa9e62aa..3845cd07accf 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -95,10 +95,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal> {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index c814dd21a519..a6cddb823372 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -94,10 +94,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map> {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index 3c8a71b48b3a..2df038f56992 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -94,10 +94,7 @@ public class AdditionalPropertiesString extends HashMap<String, String> {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Animal.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Animal.java
index cadf99c57342..21efea5d62b1 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Animal.java
@@ -131,10 +131,7 @@ public class Animal {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     /**
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 37c891ea1d93..b0c6010900a9 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -101,10 +101,7 @@ public class ArrayOfArrayOfNumberOnly {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 69e8754e6a91..ffbe7e7b1b76 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -101,10 +101,7 @@ public class ArrayOfNumberOnly {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ArrayTest.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ArrayTest.java
index 9e969a627f04..fc029c95dd18 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ArrayTest.java
@@ -173,10 +173,7 @@ public class ArrayTest {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/BigCat.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/BigCat.java
index 502f31649bce..29facf35887c 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/BigCat.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/BigCat.java
@@ -128,10 +128,7 @@ public class BigCat extends Cat {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     @Override
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Capitalization.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Capitalization.java
index e42f04d6ed2f..e420139022bf 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Capitalization.java
@@ -229,10 +229,7 @@ public class Capitalization {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Cat.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Cat.java
index 1c6b5058c4cd..2f0f7c0616e2 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Cat.java
@@ -93,10 +93,7 @@ public class Cat extends Animal {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     @Override
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Category.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Category.java
index 1fb0f9f80236..6a8304758342 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Category.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Category.java
@@ -117,10 +117,7 @@ public class Category {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ClassModel.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ClassModel.java
index 7556a2c31568..01064713d09b 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ClassModel.java
@@ -89,10 +89,7 @@ public class ClassModel {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Dog.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Dog.java
index 22c2d676be4d..0429ea55ca64 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Dog.java
@@ -93,10 +93,7 @@ public class Dog extends Animal {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     @Override
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/EnumArrays.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/EnumArrays.java
index 8ab01c8ce994..e1a30f110bc7 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/EnumArrays.java
@@ -194,10 +194,7 @@ public class EnumArrays {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/EnumTest.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/EnumTest.java
index 8e0de0a0fd60..07ac6d02215d 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/EnumTest.java
@@ -337,10 +337,7 @@ public class EnumTest {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index 2312149a1d4c..13f26fbe0bfd 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -130,10 +130,7 @@ public class FileSchemaTestClass {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/FormatTest.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/FormatTest.java
index dd72bce5353a..a747de51ce65 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/FormatTest.java
@@ -485,10 +485,7 @@ public class FormatTest {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 21d394bd1841..2e860d6c4ced 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -96,10 +96,7 @@ public class HasOnlyReadOnly {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/MapTest.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/MapTest.java
index 7c2117363cc1..6348815c3ee5 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/MapTest.java
@@ -240,10 +240,7 @@ public class MapTest {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 56c8779ced89..37fd3c418047 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -160,10 +160,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Model200Response.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Model200Response.java
index 86898cd1d500..fc119e37ea2c 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Model200Response.java
@@ -118,10 +118,7 @@ public class Model200Response {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelApiResponse.java
index 55d252b504c5..fc45f51bec55 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -146,10 +146,7 @@ public class ModelApiResponse {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelClient.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelClient.java
index 0f9e0ef38114..6aa4c760f18a 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelClient.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelClient.java
@@ -90,10 +90,7 @@ public class ModelClient {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelFile.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelFile.java
index 8a4c0cb510ab..649f256185f5 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelFile.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelFile.java
@@ -90,10 +90,7 @@ public class ModelFile {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelList.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelList.java
index 660bc83f63e6..571711a0ffcc 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelList.java
@@ -90,10 +90,7 @@ public class ModelList {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelReturn.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelReturn.java
index 9a3795f43d77..af5af1aa6194 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ModelReturn.java
@@ -90,10 +90,7 @@ public class ModelReturn {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Name.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Name.java
index 1fc4c5e46c1e..9e61438c59d8 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Name.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Name.java
@@ -151,10 +151,7 @@ public class Name {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/NumberOnly.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/NumberOnly.java
index 80cf4c604599..a7c3c4af26a0 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/NumberOnly.java
@@ -90,10 +90,7 @@ public class NumberOnly {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Order.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Order.java
index e73fd7e2962f..5f99d15ea424 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Order.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Order.java
@@ -266,10 +266,7 @@ public class Order {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/OuterComposite.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/OuterComposite.java
index 1158fc6fdaf6..531573f0630d 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/OuterComposite.java
@@ -146,10 +146,7 @@ public class OuterComposite {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Pet.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Pet.java
index 6399159802e5..1a9e11fe0f39 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Pet.java
@@ -286,10 +286,7 @@ public class Pet {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index 8e736bec161b..928e8cd810a6 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -106,10 +106,7 @@ public class ReadOnlyFirst {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/SpecialModelName.java
index bdf1d96a1426..8e48f76c4d14 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -90,10 +90,7 @@ public class SpecialModelName {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Tag.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Tag.java
index ca3b5374bac6..c04861d41d91 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/Tag.java
@@ -117,10 +117,7 @@ public class Tag {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 40d10075e676..f54bade8ceaf 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -210,10 +210,7 @@ public class TypeHolderDefault {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/TypeHolderExample.java
index 53cfef89d7a1..45b255c848c5 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -238,10 +238,7 @@ public class TypeHolderExample {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/User.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/User.java
index 549e98c91a6e..9cca2c47d49a 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/User.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/User.java
@@ -285,10 +285,7 @@ public class User {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/XmlItem.java b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/XmlItem.java
index 807cb8fe025d..2295ee8ec3db 100644
--- a/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/client/petstore/java-micronaut-client/src/main/java/org/openapitools/model/XmlItem.java
@@ -949,10 +949,7 @@ public class XmlItem {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index bd19b768358f..d345b577f6ee 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -148,10 +148,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index a475f1e50d6d..968d333ad8fc 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -131,10 +131,7 @@ public class AllOfWithSingleRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Animal.java
index 3b10bcc0c4e7..23efe84df52a 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Animal.java
@@ -143,10 +143,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 4a4a419b34f8..8beb031c9312 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -110,10 +110,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index b4af62eae54f..130f564eb343 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -110,10 +110,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayTest.java
index 19f79d19c27d..4ac5aba4a82f 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -190,10 +190,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Capitalization.java
index 37284689cc61..5486d41ad299 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -258,10 +258,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Cat.java
index 87a779f896d0..51c34f5843fb 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Cat.java
@@ -123,10 +123,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Category.java
index d856d70e0c62..6f4c3970af55 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Category.java
@@ -130,10 +130,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index f313f1798564..640064319768 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -135,10 +135,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ClassModel.java
index a4efa9ba6e37..7cd6c82008aa 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -98,10 +98,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Client.java
index be8e8b7b91c8..06b3dfc7fa0d 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Client.java
@@ -98,10 +98,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 8e4138e9d0e5..86202bc11cf3 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -100,10 +100,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Dog.java
index a553630bc8c1..2f56fdecb6f1 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Dog.java
@@ -123,10 +123,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumArrays.java
index ebdcd4de1455..8eef0490925e 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -211,10 +211,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumTest.java
index 02de0a664a4a..5fb0e65e9a67 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -494,10 +494,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index df7abdf65fcf..0966babaa407 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -142,10 +142,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 23c7be3b83ea..fb9024cbd78a 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -142,10 +142,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Foo.java
index d455506de9bb..33b9f826f591 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Foo.java
@@ -98,10 +98,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index 4aff1ee5d958..138e62c4d7fb 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -100,10 +100,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FormatTest.java
index 3294fb6ac54f..32a5cd233f8b 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -594,10 +594,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index f2d007d3c3d2..8da485fbb4a7 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -121,10 +121,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 02188b59ab45..338e686ae31b 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -121,10 +121,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/MapTest.java
index 7ed424f04e84..23467b7c7105 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/MapTest.java
@@ -263,10 +263,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index d1e2b7e818e9..0d7cc55eb3ec 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -175,10 +175,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Model200Response.java
index ccaf21216c6c..5374c6985991 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -131,10 +131,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index bcf279b3c66d..5d2be383d9a3 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -163,10 +163,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelFile.java
index dcd32dd51e26..69f7daeb9a07 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -99,10 +99,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelList.java
index 44e05db2691e..79f9818f6d4f 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelList.java
@@ -99,10 +99,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelReturn.java
index 27988f11066f..d2fd69e6c259 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -99,10 +99,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Name.java
index 20447839401f..25325d708819 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Name.java
@@ -184,10 +184,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NullableClass.java
index 184cbe929f1c..0d2090ec925d 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -656,10 +656,7 @@ public class NullableClass extends HashMap<String, Object> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NumberOnly.java
index d3591cdbafb6..db7d9f9bca0e 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -99,10 +99,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 4d2aae18bba1..ffd18a7c2d39 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -213,10 +213,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Order.java
index 563dfa93cc5c..94d5750e965a 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Order.java
@@ -296,10 +296,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterComposite.java
index b26e437c25e0..266eb83a8108 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -163,10 +163,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index d9b3771794e7..d7a42620977b 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -99,10 +99,7 @@ public class OuterObjectWithEnumProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index 70917e3078c4..5f8dc9195079 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -198,10 +198,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
index a4b5b7f659e7..98dff045456c 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
@@ -320,10 +320,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 9235fa914276..b69ded59ec7a 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -129,10 +129,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/SpecialModelName.java
index 55e34308c654..83f8d6caab00 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -99,10 +99,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Tag.java
index 78cfd038a586..681235c5f73c 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Tag.java
@@ -130,10 +130,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index c77042b15368..bc87cb415740 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -140,10 +140,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/User.java
index b4ddf6a6d278..da0a64d1368e 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/User.java
@@ -322,10 +322,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index e4f69939ccfb..7dcc42cc5a0c 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -146,10 +146,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 8ed7c79b10ca..85286944eeb2 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -129,10 +129,7 @@ public class AllOfWithSingleRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Animal.java
index c5005b75eeec..21f57dd18a8c 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Animal.java
@@ -141,10 +141,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 05aae9025b11..f999a3281c91 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index a57ad8474113..f5df05c07d07 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ArrayTest.java
index e793274a793c..afdb6c02ea85 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -189,10 +189,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Capitalization.java
index 4b14c12e2ab6..a19ecbca6559 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -260,10 +260,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Cat.java
index ca4f90125218..8567616636ac 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Cat.java
@@ -108,10 +108,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Category.java
index f1187cddc59f..4e3268d08688 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Category.java
@@ -128,10 +128,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 09fa56dca46c..f90fb147c6f1 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -120,10 +120,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ClassModel.java
index 025a660fb102..1403f962eb6b 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -95,10 +95,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Client.java
index f88005a259bb..45d082779ab1 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Client.java
@@ -95,10 +95,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 24c7e5e5ddef..a8bb6ff86252 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -97,10 +97,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Dog.java
index fc6f462d6cc1..198bddefb906 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Dog.java
@@ -108,10 +108,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/EnumArrays.java
index cc5591255b5e..75e7eadd11be 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -209,10 +209,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/EnumTest.java
index e5f3a4638594..3f8a3fd384fc 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -497,10 +497,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index b44e698bfd5b..74ae4a494093 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -140,10 +140,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/File.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/File.java
index 043be8408201..b70ab5a8d833 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/File.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/File.java
@@ -95,10 +95,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 635fd570538d..36e166a6cb75 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -140,10 +140,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Foo.java
index 91253b36f172..c2f49aed150f 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Foo.java
@@ -95,10 +95,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index c2b9015e9db8..ac5fce79dae8 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -97,10 +97,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/FormatTest.java
index cfdb9d5bfcf1..306b96c63ff0 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -606,10 +606,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 999bb3d641ca..ba26a40df849 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -117,10 +117,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 4775b3968f8b..aa053a4fe403 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -117,10 +117,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/MapTest.java
index 8f319ded5586..12b35f05d019 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/MapTest.java
@@ -263,10 +263,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 5b8ba25078c0..0c0afe5ac99b 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -174,10 +174,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Model200Response.java
index f96277c73eec..ae3667d54870 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -129,10 +129,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index de8a56cf0fed..c08b94715e5e 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -162,10 +162,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ModelList.java
index b8b0ff69d52b..068f29bcd09c 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ModelList.java
@@ -96,10 +96,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ModelReturn.java
index 3bdefdbe181b..a7c0f9214aa5 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -96,10 +96,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Name.java
index 47017abeaf98..0628b072cf09 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Name.java
@@ -182,10 +182,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/NullableClass.java
index 9f03718dcc00..ab4c29b09b04 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -664,10 +664,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/NumberOnly.java
index 36d4f5cd0f62..de65f8c39a85 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -96,10 +96,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 99b8a10686d4..65453cbc9271 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -213,10 +213,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Order.java
index 59f1df3d405a..fcf09a02e6aa 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Order.java
@@ -298,10 +298,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/OuterComposite.java
index d6d586303746..0e01ae11a722 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -162,10 +162,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 675efcca5779..a06953c57d37 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -96,10 +96,7 @@ public class OuterObjectWithEnumProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index 8e14e218d1fc..db2d19ec8f19 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -195,10 +195,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Pet.java
index a10e99bcd2e2..5da2483a54d9 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Pet.java
@@ -322,10 +322,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 805c0b620ba2..6b439a29d776 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -125,10 +125,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/SpecialModelName.java
index aba001bad4a2..ba4d6f65b975 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -96,10 +96,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Tag.java
index a54d41577ae7..869637345a3a 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/Tag.java
@@ -128,10 +128,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 47de6bbb5203..38a33f15e80a 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -145,10 +145,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/User.java
index 6045ffb8c9ce..2e7d127b1883 100644
--- a/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/feign-hc5/src/main/java/org/openapitools/client/model/User.java
@@ -326,10 +326,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
index 03b27de576d1..71ed54fcd782 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
@@ -142,10 +142,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
index a04fa169e783..2fda72785f41 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
@@ -143,10 +143,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
index f6395226dcc7..f4a484ba72a7 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
@@ -142,10 +142,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index d8ad61f87287..73297013f8be 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -492,10 +492,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
index 2364fd43200f..4cb33902bbe9 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
@@ -142,10 +142,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
index 7b9170e97c37..9267d7b03de8 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
@@ -143,10 +143,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
index afda110c51ba..3dc532b71a40 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
@@ -143,10 +143,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
index e8a09347d713..1bbb3875b06e 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
@@ -142,10 +142,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Animal.java
index de3eaf90f949..d2b5ac9b37a2 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Animal.java
@@ -141,10 +141,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index eeaa55188c1a..e0822976909d 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -106,10 +106,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index c3bd5811bd98..699c91bc5ecd 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -106,10 +106,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayTest.java
index 31754d718b12..1921feafdd85 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -188,10 +188,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/BigCat.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/BigCat.java
index a360314e0ab7..b004b66418f2 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/BigCat.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/BigCat.java
@@ -145,10 +145,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Capitalization.java
index 0fd063f0e237..32a3b1f60c87 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -259,10 +259,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Cat.java
index de493c78d360..b0a85211a52f 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Cat.java
@@ -109,10 +109,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Category.java
index da2c27e6ed7e..76604b231071 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Category.java
@@ -127,10 +127,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ClassModel.java
index e3b4b553408b..7b57c161b01f 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -95,10 +95,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Client.java
index cd8c8dd3f903..e521c4a031b4 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Client.java
@@ -94,10 +94,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Dog.java
index 0cacbacf9638..14e8e6856fdc 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Dog.java
@@ -106,10 +106,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/EnumArrays.java
index a7291bc236ac..404486e0f943 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -208,10 +208,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/EnumTest.java
index 1d54171f4ed4..49a80725d6c1 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -372,10 +372,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/File.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/File.java
index 79bbe98b143e..adfd0c079e25 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/File.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/File.java
@@ -95,10 +95,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index adecdc601a15..7cd5503b9104 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -139,10 +139,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/FormatTest.java
index d4ebb5eaf1ef..a17906e1064f 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -539,10 +539,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index bd212afd4c8a..43c846e0a3b1 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -116,10 +116,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/MapTest.java
index 0e31a44ae396..c4c5dc45eb36 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/MapTest.java
@@ -262,10 +262,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 40484faff007..e97fcdcee629 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -173,10 +173,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Model200Response.java
index d98bc71ec066..527f4dae30ea 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -129,10 +129,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index a4d167423319..b7defb6a9d35 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -161,10 +161,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ModelList.java
index cd82e22589d5..23df87c79c6d 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ModelList.java
@@ -95,10 +95,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ModelReturn.java
index 781996ba8503..cdad94fbd8ae 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -96,10 +96,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Name.java
index 85255fc376f3..a649ddd80951 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Name.java
@@ -182,10 +182,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/NumberOnly.java
index 2808136d7980..b124415ea7cf 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -95,10 +95,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Order.java
index 976aa6435ea0..2a0be3bebd7b 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Order.java
@@ -297,10 +297,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/OuterComposite.java
index 36f1289ed10b..834f91845d6d 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -161,10 +161,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Pet.java
index bef619df2a46..4d8b752c3e59 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Pet.java
@@ -321,10 +321,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 8d96d31f5e60..8b0509849ae8 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -124,10 +124,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/SpecialModelName.java
index ef4ac42d29e1..81a4060e757c 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -95,10 +95,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Tag.java
index 2a427714646e..0e93e2507d07 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Tag.java
@@ -127,10 +127,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/TypeHolderDefault.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
index 8c0b99f70cb3..c6edd44e0057 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
@@ -238,10 +238,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/TypeHolderExample.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/TypeHolderExample.java
index ed32a645403c..91b439855fce 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/TypeHolderExample.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/TypeHolderExample.java
@@ -271,10 +271,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/User.java
index d17f01bf0fe1..4b8b5536903e 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/User.java
@@ -325,10 +325,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/XmlItem.java
index 3f90feadd111..0c6a13ef5fa0 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -1094,10 +1094,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index e4f69939ccfb..7dcc42cc5a0c 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -146,10 +146,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 8ed7c79b10ca..85286944eeb2 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -129,10 +129,7 @@ public class AllOfWithSingleRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Animal.java
index c5005b75eeec..21f57dd18a8c 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Animal.java
@@ -141,10 +141,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 05aae9025b11..f999a3281c91 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index a57ad8474113..f5df05c07d07 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayTest.java
index e793274a793c..afdb6c02ea85 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -189,10 +189,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Capitalization.java
index 4b14c12e2ab6..a19ecbca6559 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -260,10 +260,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Cat.java
index ca4f90125218..8567616636ac 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Cat.java
@@ -108,10 +108,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Category.java
index f1187cddc59f..4e3268d08688 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Category.java
@@ -128,10 +128,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 09fa56dca46c..f90fb147c6f1 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -120,10 +120,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ClassModel.java
index 025a660fb102..1403f962eb6b 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -95,10 +95,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Client.java
index f88005a259bb..45d082779ab1 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Client.java
@@ -95,10 +95,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 24c7e5e5ddef..a8bb6ff86252 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -97,10 +97,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Dog.java
index fc6f462d6cc1..198bddefb906 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Dog.java
@@ -108,10 +108,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/EnumArrays.java
index cc5591255b5e..75e7eadd11be 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -209,10 +209,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/EnumTest.java
index e5f3a4638594..3f8a3fd384fc 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -497,10 +497,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index b44e698bfd5b..74ae4a494093 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -140,10 +140,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/File.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/File.java
index 043be8408201..b70ab5a8d833 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/File.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/File.java
@@ -95,10 +95,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 635fd570538d..36e166a6cb75 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -140,10 +140,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Foo.java
index 91253b36f172..c2f49aed150f 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Foo.java
@@ -95,10 +95,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index c2b9015e9db8..ac5fce79dae8 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -97,10 +97,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FormatTest.java
index cfdb9d5bfcf1..306b96c63ff0 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -606,10 +606,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 999bb3d641ca..ba26a40df849 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -117,10 +117,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 4775b3968f8b..aa053a4fe403 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -117,10 +117,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/MapTest.java
index 8f319ded5586..12b35f05d019 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/MapTest.java
@@ -263,10 +263,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 5b8ba25078c0..0c0afe5ac99b 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -174,10 +174,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Model200Response.java
index f96277c73eec..ae3667d54870 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -129,10 +129,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index de8a56cf0fed..c08b94715e5e 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -162,10 +162,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ModelList.java
index b8b0ff69d52b..068f29bcd09c 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ModelList.java
@@ -96,10 +96,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ModelReturn.java
index 3bdefdbe181b..a7c0f9214aa5 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -96,10 +96,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Name.java
index 47017abeaf98..0628b072cf09 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Name.java
@@ -182,10 +182,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/NullableClass.java
index 9f03718dcc00..ab4c29b09b04 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -664,10 +664,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/NumberOnly.java
index 36d4f5cd0f62..de65f8c39a85 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -96,10 +96,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 99b8a10686d4..65453cbc9271 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -213,10 +213,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Order.java
index 59f1df3d405a..fcf09a02e6aa 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Order.java
@@ -298,10 +298,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/OuterComposite.java
index d6d586303746..0e01ae11a722 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -162,10 +162,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 675efcca5779..a06953c57d37 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -96,10 +96,7 @@ public class OuterObjectWithEnumProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index 8e14e218d1fc..db2d19ec8f19 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -195,10 +195,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Pet.java
index a10e99bcd2e2..5da2483a54d9 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Pet.java
@@ -322,10 +322,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 805c0b620ba2..6b439a29d776 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -125,10 +125,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/SpecialModelName.java
index aba001bad4a2..ba4d6f65b975 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -96,10 +96,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Tag.java
index a54d41577ae7..869637345a3a 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Tag.java
@@ -128,10 +128,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 47de6bbb5203..38a33f15e80a 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -145,10 +145,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/User.java
index 6045ffb8c9ce..2e7d127b1883 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/User.java
@@ -326,10 +326,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
index 447d5f69ae38..6a29be81285c 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
@@ -136,10 +136,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
index 2983e410b129..91cb7ea80f44 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
@@ -137,10 +137,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
index aaddf57fe39a..02ecbeafddb7 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
@@ -136,10 +136,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 860bcc928ff0..22469fb9fb92 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -483,10 +483,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
index c33954a06ff4..0244b022ede0 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
@@ -136,10 +136,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
index 3d29a210c7be..e650999ab964 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
@@ -137,10 +137,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
index 39375d02f6b2..4699ea278abb 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
@@ -136,10 +136,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
index e79b53cafc38..78e9777e44c1 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
@@ -136,10 +136,7 @@ public class AdditionalPropertiesString extends HashMap<String, String> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Animal.java
index 0282c5ffdde7..fcbee7978638 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Animal.java
@@ -141,10 +141,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 05aae9025b11..f999a3281c91 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index a57ad8474113..f5df05c07d07 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayTest.java
index 3dfa034fec8c..0c22d54edea7 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -187,10 +187,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/BigCat.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/BigCat.java
index 32c6cdd95506..38e9d3f7b9ff 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/BigCat.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/BigCat.java
@@ -159,10 +159,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Capitalization.java
index b2db0dd9497c..96cb38ffbd3a 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -255,10 +255,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Cat.java
index 06750c1b7a5c..4af5a2846af5 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Cat.java
@@ -123,10 +123,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Category.java
index b06cb8f143e1..c56efa1b8a0b 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Category.java
@@ -127,10 +127,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ClassModel.java
index 025a660fb102..1403f962eb6b 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -95,10 +95,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Client.java
index f88005a259bb..45d082779ab1 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Client.java
@@ -95,10 +95,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Dog.java
index 3dd517f475d9..0095b95b0c7c 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Dog.java
@@ -120,10 +120,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/EnumArrays.java
index 9da3fa9a02a2..8dbd1f17a19f 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -208,10 +208,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/EnumTest.java
index cfa2ee140da7..8d41cb7c4a41 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -369,10 +369,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 6ed704664d75..308d71e3c0c7 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -139,10 +139,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/FormatTest.java
index ec769ad8ed1f..2187f0176103 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -527,10 +527,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 0a02e6ac5bd2..3abffcdb884c 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -118,10 +118,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/MapTest.java
index 10cbd3663bf0..7fb194942948 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/MapTest.java
@@ -260,10 +260,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 148ff9614e56..faa706c19210 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -172,10 +172,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Model200Response.java
index 0662306cdfba..f555afa8b655 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -128,10 +128,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index c953c34819d3..c80bdaaf8c77 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -160,10 +160,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ModelFile.java
index 715f1a5940a4..7cabeb1588a8 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -96,10 +96,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ModelList.java
index b8b0ff69d52b..068f29bcd09c 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ModelList.java
@@ -96,10 +96,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ModelReturn.java
index 3bdefdbe181b..a7c0f9214aa5 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -96,10 +96,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Name.java
index b1fc0834268c..75523ca8acc0 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Name.java
@@ -181,10 +181,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/NumberOnly.java
index 36d4f5cd0f62..de65f8c39a85 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -96,10 +96,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Order.java
index 7e5b39766e8f..642eccbc1384 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Order.java
@@ -293,10 +293,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/OuterComposite.java
index 2c9c2d8be38e..60c4a04e7dff 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -160,10 +160,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Pet.java
index 2fddb31d41f8..5681216244a3 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Pet.java
@@ -317,10 +317,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index b341198f23f4..a9faae1c3d41 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -126,10 +126,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/SpecialModelName.java
index a3340c31a0c4..e7e62b054e88 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -96,10 +96,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Tag.java
index 4a44520fada0..ceb3d1ed3036 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Tag.java
@@ -127,10 +127,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/TypeHolderDefault.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
index 8dde1ca504e9..1287f8590068 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
@@ -235,10 +235,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/TypeHolderExample.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/TypeHolderExample.java
index 96348a7f852c..4dd1c0b5d6b1 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/TypeHolderExample.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/TypeHolderExample.java
@@ -267,10 +267,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/User.java
index 8427dda3f605..c871f7cb2a2f 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/User.java
@@ -319,10 +319,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/XmlItem.java
index 0777259cafe1..6d5959651f2d 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -1067,10 +1067,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 925c0becb002..4f695fdbd251 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -107,10 +107,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
index 00eb66046a68..f7e237a69124 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
@@ -143,10 +143,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
index 3d55448939d5..ffb01262b78f 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
@@ -144,10 +144,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
index e38ad356fc5f..5d1903004dcf 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
@@ -143,10 +143,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index a27b86b66847..eafb176eb76c 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -488,10 +488,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
index 207d8b26ba5c..6b6521fd5d47 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
@@ -143,10 +143,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
index ad34fa8faf89..df3ed8666817 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
@@ -144,10 +144,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
index ffc2df318ed5..734b91447afd 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
@@ -144,10 +144,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
index 0622086361f9..9c49431b79fc 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
@@ -143,10 +143,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Animal.java
index 68e572c899b7..cffcf1b4c74f 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Animal.java
@@ -146,10 +146,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 93d5ac87c962..7461fb1fd58e 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -111,10 +111,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 649aadee4210..5630a5c37b68 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -111,10 +111,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayTest.java
index aae9cd01c594..f9020e897037 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -191,10 +191,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/BigCat.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/BigCat.java
index e3bace499258..35ca74ad57c5 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/BigCat.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/BigCat.java
@@ -151,10 +151,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Capitalization.java
index b53f9d6afce4..ec362c8fc72d 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -260,10 +260,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Cat.java
index 7f27e91463a3..abf27bc1b98c 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Cat.java
@@ -115,10 +115,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Category.java
index f8f9a44245b4..7fd9e3a98aa4 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Category.java
@@ -132,10 +132,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ClassModel.java
index cacca185c389..bd693b7da467 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -100,10 +100,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Client.java
index 55df7d155a54..a37bdf670832 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Client.java
@@ -100,10 +100,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Dog.java
index e6a373cc8529..6e5b70ef535b 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Dog.java
@@ -112,10 +112,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/EnumArrays.java
index 22c6d6ad4496..459e2d9f3337 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -212,10 +212,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/EnumTest.java
index 2965e6697acb..4c1e606fe0d9 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -374,10 +374,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index f0871ba4e84b..4adc37d3c3b0 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -143,10 +143,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/FormatTest.java
index 665c4d375cd2..f77db844353e 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -532,10 +532,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 5f0a506f30f7..ef898a4c1e4f 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -123,10 +123,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/MapTest.java
index 8ce18b9354bf..dbc1a4373578 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/MapTest.java
@@ -265,10 +265,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index f3e3fcddd40f..a84b05b4ae40 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -177,10 +177,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Model200Response.java
index fafbf6b851cb..041d72b1f92f 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -133,10 +133,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index c178793239bc..2b4be28c0d67 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -165,10 +165,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ModelFile.java
index 2493eab1b496..624b2b150771 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -101,10 +101,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ModelList.java
index 61dcc0ca11b3..3f17555ca1be 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ModelList.java
@@ -101,10 +101,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ModelReturn.java
index 2277f1b33709..89d6cf82b9d5 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -101,10 +101,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Name.java
index adc51dc5d2c9..fa00b300655e 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Name.java
@@ -186,10 +186,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/NumberOnly.java
index f5878d2159b6..2ffe6efd7574 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -101,10 +101,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Order.java
index 7bc6b0e29da3..d710fe6a90cf 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Order.java
@@ -298,10 +298,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/OuterComposite.java
index 0aa179c2649c..5afbf88ccb4f 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -165,10 +165,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Pet.java
index 992eb3299a60..ea21402a8b3d 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Pet.java
@@ -321,10 +321,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 819a74266510..f44e21cec6aa 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -130,10 +130,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/SpecialModelName.java
index 23b1df0c5215..4b77e9335fca 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -101,10 +101,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Tag.java
index 9e3d96ab6557..80ab66c23fd3 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Tag.java
@@ -132,10 +132,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/TypeHolderDefault.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
index 54a34f81fa16..37fed3094cbe 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
@@ -239,10 +239,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/TypeHolderExample.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/TypeHolderExample.java
index 88b8b1e9d9bf..5ec87a7b70a1 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/TypeHolderExample.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/TypeHolderExample.java
@@ -271,10 +271,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/User.java
index c08145d34a00..573970b65acb 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/User.java
@@ -324,10 +324,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/XmlItem.java
index fb8eaf0efdd9..fbaaa04dd145 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -1071,10 +1071,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 925c0becb002..4f695fdbd251 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -107,10 +107,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
index 00eb66046a68..f7e237a69124 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
@@ -143,10 +143,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
index 3d55448939d5..ffb01262b78f 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
@@ -144,10 +144,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
index e38ad356fc5f..5d1903004dcf 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
@@ -143,10 +143,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index a27b86b66847..eafb176eb76c 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -488,10 +488,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
index 207d8b26ba5c..6b6521fd5d47 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
@@ -143,10 +143,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
index ad34fa8faf89..df3ed8666817 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
@@ -144,10 +144,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
index ffc2df318ed5..734b91447afd 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
@@ -144,10 +144,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
index 0622086361f9..9c49431b79fc 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
@@ -143,10 +143,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Animal.java
index 68e572c899b7..cffcf1b4c74f 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Animal.java
@@ -146,10 +146,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 93d5ac87c962..7461fb1fd58e 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -111,10 +111,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 649aadee4210..5630a5c37b68 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -111,10 +111,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayTest.java
index aae9cd01c594..f9020e897037 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -191,10 +191,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/BigCat.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/BigCat.java
index e3bace499258..35ca74ad57c5 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/BigCat.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/BigCat.java
@@ -151,10 +151,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Capitalization.java
index b53f9d6afce4..ec362c8fc72d 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -260,10 +260,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Cat.java
index 7f27e91463a3..abf27bc1b98c 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Cat.java
@@ -115,10 +115,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Category.java
index f8f9a44245b4..7fd9e3a98aa4 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Category.java
@@ -132,10 +132,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ClassModel.java
index cacca185c389..bd693b7da467 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -100,10 +100,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Client.java
index 55df7d155a54..a37bdf670832 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Client.java
@@ -100,10 +100,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Dog.java
index e6a373cc8529..6e5b70ef535b 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Dog.java
@@ -112,10 +112,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumArrays.java
index 22c6d6ad4496..459e2d9f3337 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -212,10 +212,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumTest.java
index 2965e6697acb..4c1e606fe0d9 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -374,10 +374,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index f0871ba4e84b..4adc37d3c3b0 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -143,10 +143,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FormatTest.java
index 51243bfb43c5..bfae69b70600 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -532,10 +532,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 5f0a506f30f7..ef898a4c1e4f 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -123,10 +123,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/MapTest.java
index 8ce18b9354bf..dbc1a4373578 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/MapTest.java
@@ -265,10 +265,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index b777c829dc07..01073595e305 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -177,10 +177,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Model200Response.java
index fafbf6b851cb..041d72b1f92f 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -133,10 +133,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index c178793239bc..2b4be28c0d67 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -165,10 +165,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelFile.java
index 2493eab1b496..624b2b150771 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -101,10 +101,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelList.java
index 61dcc0ca11b3..3f17555ca1be 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelList.java
@@ -101,10 +101,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelReturn.java
index 2277f1b33709..89d6cf82b9d5 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -101,10 +101,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Name.java
index adc51dc5d2c9..fa00b300655e 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Name.java
@@ -186,10 +186,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NumberOnly.java
index f5878d2159b6..2ffe6efd7574 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -101,10 +101,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Order.java
index ac3e76c9351f..4fd70541b731 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Order.java
@@ -298,10 +298,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/OuterComposite.java
index 0aa179c2649c..5afbf88ccb4f 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -165,10 +165,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Pet.java
index 992eb3299a60..ea21402a8b3d 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Pet.java
@@ -321,10 +321,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 819a74266510..f44e21cec6aa 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -130,10 +130,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/SpecialModelName.java
index 23b1df0c5215..4b77e9335fca 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -101,10 +101,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Tag.java
index 9e3d96ab6557..80ab66c23fd3 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Tag.java
@@ -132,10 +132,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/TypeHolderDefault.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
index 54a34f81fa16..37fed3094cbe 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
@@ -239,10 +239,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/TypeHolderExample.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/TypeHolderExample.java
index 88b8b1e9d9bf..5ec87a7b70a1 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/TypeHolderExample.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/TypeHolderExample.java
@@ -271,10 +271,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/User.java
index c08145d34a00..573970b65acb 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/User.java
@@ -324,10 +324,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/XmlItem.java
index fb8eaf0efdd9..fbaaa04dd145 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -1071,10 +1071,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3-oneOf/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/jersey3-oneOf/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index eae109bc73e6..215919bd3f11 100644
--- a/samples/client/petstore/java/jersey3-oneOf/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/jersey3-oneOf/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -107,10 +107,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/jersey3-oneOf/src/main/java/org/openapitools/client/model/SchemaA.java b/samples/client/petstore/java/jersey3-oneOf/src/main/java/org/openapitools/client/model/SchemaA.java
index 0ee238b2e43b..29a9acf51a50 100644
--- a/samples/client/petstore/java/jersey3-oneOf/src/main/java/org/openapitools/client/model/SchemaA.java
+++ b/samples/client/petstore/java/jersey3-oneOf/src/main/java/org/openapitools/client/model/SchemaA.java
@@ -101,10 +101,7 @@ public class SchemaA {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index b515f20d6f91..b2677690da5a 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -107,10 +107,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index e556f7d0d87f..c1034eb54071 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -379,10 +379,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
index 62ef9556da9e..50cab9c95b4c 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
@@ -98,10 +98,7 @@ public class AllOfRefToDouble {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
index 67d33b78c3af..27587b16c73b 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
@@ -98,10 +98,7 @@ public class AllOfRefToFloat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AllOfRefToLong.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
index b021890fad9b..59ffea06d3b7 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
@@ -98,10 +98,7 @@ public class AllOfRefToLong {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Animal.java
index 1592ceb1c2ea..5e7f56ccc82f 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Animal.java
@@ -144,10 +144,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Apple.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Apple.java
index cdf3f5afefe4..088c87561fd0 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Apple.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Apple.java
@@ -131,10 +131,7 @@ public class Apple {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AppleReq.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AppleReq.java
index 045942a1fce0..dd66d0778b93 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AppleReq.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/AppleReq.java
@@ -132,10 +132,7 @@ public class AppleReq {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 1f2c39159b79..24a7cd0cb8ed 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -110,10 +110,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index a4c073b3c05c..782f14564db6 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -110,10 +110,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayTest.java
index 7b7ba72b6cc5..e3be58f901ce 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -191,10 +191,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Banana.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Banana.java
index f08d6d95e0e0..66a05e12a908 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Banana.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Banana.java
@@ -101,10 +101,7 @@ public class Banana {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/BananaReq.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/BananaReq.java
index 2b0beac97e8d..44a582903416 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/BananaReq.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/BananaReq.java
@@ -134,10 +134,7 @@ public class BananaReq {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/BasquePig.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/BasquePig.java
index 03946b666f58..d17623e1f4fa 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/BasquePig.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/BasquePig.java
@@ -99,10 +99,7 @@ public class BasquePig {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Capitalization.java
index 1fdf127c7283..af64e9ea72ae 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -258,10 +258,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Cat.java
index 1a51b20d1ec0..14eea74ffa0a 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Cat.java
@@ -152,10 +152,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Category.java
index 625021223745..9e0193380db0 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Category.java
@@ -131,10 +131,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ChildCat.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ChildCat.java
index d1d475cf1802..7dd0673ff847 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ChildCat.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ChildCat.java
@@ -197,10 +197,7 @@ public class ChildCat extends ParentPet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ClassModel.java
index 1261f042021e..755b06511824 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -98,10 +98,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Client.java
index d7c39ed07d4d..5c280121dbbf 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Client.java
@@ -98,10 +98,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
index 83bbe3d6aab0..cdc32a4b29b1 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
@@ -174,10 +174,7 @@ public class ComplexQuadrilateral {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/DanishPig.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/DanishPig.java
index 7a1a98b30ef9..8dc7966aec9c 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/DanishPig.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/DanishPig.java
@@ -99,10 +99,7 @@ public class DanishPig {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index b5fd3115f884..2fec96b73988 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -100,10 +100,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Dog.java
index ec6ae1c723d8..6a72f62f0d15 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Dog.java
@@ -151,10 +151,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Drawing.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Drawing.java
index 213c18b34ce1..64e7f8aad97b 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Drawing.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Drawing.java
@@ -283,10 +283,7 @@ public class Drawing {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EnumArrays.java
index 4359a03c6c56..00d960e38360 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -210,10 +210,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EnumTest.java
index 47c48b3bfadd..8777b31b1258 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -565,10 +565,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EquilateralTriangle.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
index 0f5132bdb8ca..97ac94da469f 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
@@ -174,10 +174,7 @@ public class EquilateralTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 133177b296b1..a591e500c494 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -143,10 +143,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Foo.java
index 56a9cb0027a6..6e2fab35e07a 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Foo.java
@@ -98,10 +98,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index 14727a61ce27..011fb2935df3 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -101,10 +101,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FormatTest.java
index d6daf1cc2c8f..4163579f085d 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -604,10 +604,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/GrandparentAnimal.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
index 91d9565e141c..2a58a4d16679 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
@@ -112,10 +112,7 @@ public class GrandparentAnimal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index cb05541b3788..557673deac7f 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -121,10 +121,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 684b8979b6cc..522996134ab5 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -120,10 +120,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
index 5884127e4015..c1bc7bf66bf6 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
@@ -132,10 +132,7 @@ public class IsoscelesTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/MapTest.java
index e631353c5533..ead35206989b 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/MapTest.java
@@ -264,10 +264,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index caf054f73edb..20bcfe584c1b 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -178,10 +178,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Model200Response.java
index 4373ad306007..27f52d032e7c 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -131,10 +131,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 2bd716913471..bff886e3efa7 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -163,10 +163,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ModelFile.java
index 937f59570316..b58e31146369 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -99,10 +99,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ModelList.java
index 375f8d20fb6e..1adb6ddd29cb 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ModelList.java
@@ -99,10 +99,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ModelReturn.java
index 66e91929f8b5..db3fb4fce9c9 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -99,10 +99,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Name.java
index df721a0e6aef..ca25822a455d 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Name.java
@@ -185,10 +185,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/NullableClass.java
index e58112d57e79..f2ff99227fa5 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -651,10 +651,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/NumberOnly.java
index 4c2ae8c66393..1938b1335d14 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -100,10 +100,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 2a61b7f0a6c8..7e4bdb1b739f 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -223,10 +223,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Order.java
index f3ebf3f247fe..d7a2dd6fa8bd 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Order.java
@@ -297,10 +297,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/OuterComposite.java
index c8d6f14f78aa..61aad123a2c3 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -164,10 +164,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ParentPet.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ParentPet.java
index 650b7adec9b2..0036600b2997 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ParentPet.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ParentPet.java
@@ -122,10 +122,7 @@ public class ParentPet extends GrandparentAnimal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Pet.java
index 62325c5434b0..2c58d2cccbd0 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Pet.java
@@ -319,10 +319,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
index c2ff347b1d38..87f4008bf44d 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
@@ -99,10 +99,7 @@ public class QuadrilateralInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index f4d4781750ed..2377d16f97c1 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -128,10 +128,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ScaleneTriangle.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
index db1806627bdf..9ef9b5ed0548 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
@@ -174,10 +174,7 @@ public class ScaleneTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ShapeInterface.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ShapeInterface.java
index b22be2bdf7df..3012bd12aa21 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ShapeInterface.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ShapeInterface.java
@@ -99,10 +99,7 @@ public class ShapeInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
index 4c2182cea6a4..9c9f6fb6c2dd 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
@@ -174,10 +174,7 @@ public class SimpleQuadrilateral {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/SpecialModelName.java
index 644a149d66f9..7ff29e304d3e 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -131,10 +131,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Tag.java
index 7c50bce8a870..a5750d34926c 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Tag.java
@@ -130,10 +130,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 5c77972828fc..71ab38ca2802 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -141,10 +141,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/TriangleInterface.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/TriangleInterface.java
index 5869a425b2ec..78c1430926b9 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/TriangleInterface.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/TriangleInterface.java
@@ -99,10 +99,7 @@ public class TriangleInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/User.java
index 5d119970e6c0..673f988a9f42 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/User.java
@@ -486,10 +486,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Whale.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Whale.java
index 07b74b4fc4e1..184d4bc2af69 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Whale.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Whale.java
@@ -164,10 +164,7 @@ public class Whale {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Zebra.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Zebra.java
index 620bdaca7e69..6c04c4b779e5 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Zebra.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Zebra.java
@@ -211,10 +211,7 @@ public class Zebra {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/Category.java
index fd94b02cd9a1..0daa6c2aad4a 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/Category.java
@@ -128,10 +128,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index c7d8400e29e2..e20f277173a6 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -160,10 +160,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/Order.java
index ea86cb3c2d44..139d2d7b5731 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/Order.java
@@ -288,10 +288,7 @@ public class Order  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/Pet.java
index 85a6e0a6df6a..ec3581850b64 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/Pet.java
@@ -310,10 +310,7 @@ public class Pet  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/Tag.java
index 5799702c6109..86d37a8da3e7 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/Tag.java
@@ -128,10 +128,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/User.java
index 9abeb0815def..9a8a80852d17 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-mutiny/src/main/java/org/openapitools/client/model/User.java
@@ -317,10 +317,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/Category.java
index f28adf38bab4..32176b533a4b 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/Category.java
@@ -143,10 +143,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 55d06d795c79..840bd75e16cb 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -177,10 +177,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/Order.java
index f2c037150429..4cecac6f1fc3 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/Order.java
@@ -315,10 +315,7 @@ public class Order  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/Pet.java
index 922d8be21c2f..5a1126dab383 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/Pet.java
@@ -343,10 +343,7 @@ public class Pet  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/Tag.java
index 82c149591b4e..4cbbbe89331c 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/Tag.java
@@ -143,10 +143,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/User.java
index 0649da03757c..d573cf4c1792 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml/src/main/java/org/openapitools/client/model/User.java
@@ -344,10 +344,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 897e1c1c7b10..4c944eefe9cd 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -137,10 +137,7 @@ public class AdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 87a31ffdd638..95bc8f4686f2 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -120,10 +120,7 @@ public class AllOfWithSingleRef  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Animal.java
index a1da7362475f..e15d6484097c 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Animal.java
@@ -132,10 +132,7 @@ public class Animal  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 71a1209a7d71..a1bc31b0a43a 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -101,10 +101,7 @@ public class ArrayOfArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 5e1f342cf668..4e32dc62dd60 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -101,10 +101,7 @@ public class ArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ArrayTest.java
index 73ccd377d66d..814a1707a763 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -177,10 +177,7 @@ public class ArrayTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Capitalization.java
index d20db7a83766..f5fd55afeab4 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -242,10 +242,7 @@ public class Capitalization  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Cat.java
index 76f5fced65a8..31ab055e58ff 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Cat.java
@@ -99,10 +99,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Category.java
index bceefba0f22a..c1f7e2a0dc93 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Category.java
@@ -119,10 +119,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 53beb74fc732..c0e155a4d9a8 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -99,10 +99,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ClassModel.java
index 78e299ebe2b0..95d1ff3062a5 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -92,10 +92,7 @@ public class ClassModel  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Client.java
index dc6c4bda41e8..11e1453e654c 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Client.java
@@ -89,10 +89,7 @@ public class Client  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index cfb2da225988..5b18fec25228 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -89,10 +89,7 @@ public class DeprecatedObject  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Dog.java
index 1694ead103a5..e72b39c0abe8 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Dog.java
@@ -99,10 +99,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/EnumArrays.java
index 8724d1d201b6..226389c50c14 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -194,10 +194,7 @@ public class EnumArrays  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/EnumTest.java
index 623c6359b044..3adf0c54e340 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -432,10 +432,7 @@ public class EnumTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index 32f9a30eace5..0d776a6dcfc8 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -131,10 +131,7 @@ public class FakeBigDecimalMap200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 16ed21466d94..aa4ca5d3b130 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -131,10 +131,7 @@ public class FileSchemaTestClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Foo.java
index c57985a5ba74..0eb65dc09e2a 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Foo.java
@@ -89,10 +89,7 @@ public class Foo  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index 0b1b39d0c391..ced851d2e4bb 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -91,10 +91,7 @@ public class FooGetDefaultResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/FormatTest.java
index 01123b2103c6..f515da9595e8 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -560,10 +560,7 @@ public class FormatTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 113c5f6b39b3..d5e5d682b84a 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -106,10 +106,7 @@ public class HasOnlyReadOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 8e25ef7f1acc..aaa5c6e3fe4d 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -92,10 +92,7 @@ public class HealthCheckResult  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/MapTest.java
index 69aec1720ea3..c32fd621158d 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/MapTest.java
@@ -245,10 +245,7 @@ public class MapTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 2df3e63bbc9b..ae36a9b5bf5f 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -162,10 +162,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Model200Response.java
index d05dac0e6a68..596fc98172f5 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -123,10 +123,7 @@ public class Model200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 6d7e5314c738..2af737b84f5d 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -150,10 +150,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ModelFile.java
index 2301cb17c6cc..6d430628490d 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -96,10 +96,7 @@ public class ModelFile  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ModelList.java
index cf9f644a98fa..0f21bdab5a4d 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ModelList.java
@@ -90,10 +90,7 @@ public class ModelList  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ModelReturn.java
index 5c27bd0004b2..ec60fa4fa680 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -93,10 +93,7 @@ public class ModelReturn  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Name.java
index 1dd4e56264d4..37036db756be 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Name.java
@@ -168,10 +168,7 @@ public class Name  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/NullableClass.java
index e9fcc6355c8d..51bb625c0d5f 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -518,10 +518,7 @@ public class NullableClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/NumberOnly.java
index 88a2052497dc..5b32f5c17a49 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -90,10 +90,7 @@ public class NumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 6798ad29853a..1a836a4ce39b 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -198,10 +198,7 @@ public class ObjectWithDeprecatedFields  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Order.java
index a641e58ab938..0b4e6b00238f 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Order.java
@@ -275,10 +275,7 @@ public class Order  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/OuterComposite.java
index 558ea9193ccd..80bdfb65bc2c 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -150,10 +150,7 @@ public class OuterComposite  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 7e189abf45de..45d330ad2ec8 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -90,10 +90,7 @@ public class OuterObjectWithEnumProperty  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index b4b9017e87c5..1337cc0067c8 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -163,10 +163,7 @@ public class ParentWithNullable  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Pet.java
index c0b22f8d59a2..1dbec78aaf34 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Pet.java
@@ -299,10 +299,7 @@ public class Pet  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 9a1c0542323e..5c088924b084 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -116,10 +116,7 @@ public class ReadOnlyFirst  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/SpecialModelName.java
index d4a29fe39f28..6096da78c2f6 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -90,10 +90,7 @@ public class SpecialModelName  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Tag.java
index 750a051990ae..8707e1f596d1 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/Tag.java
@@ -119,10 +119,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index c87b005cd429..565d3bd652e9 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -134,10 +134,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/User.java
index f8daf8aba76b..72950a8e4316 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-jackson/src/main/java/org/openapitools/client/model/User.java
@@ -302,10 +302,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/Category.java
index bbc2e617e395..a5d994a97f0c 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/Category.java
@@ -121,10 +121,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 0e34b097d22e..68d0b586a919 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -146,10 +146,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/Order.java
index 439ac6b1e9a1..559326f53c0d 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/Order.java
@@ -267,10 +267,7 @@ public class Order  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/Pet.java
index 5b36d5667569..ac698fbe3e55 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/Pet.java
@@ -289,10 +289,7 @@ public class Pet  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/Tag.java
index ca7bbc3159cf..4b2b0c3000ea 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/Tag.java
@@ -121,10 +121,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/User.java
index 60a914361519..085d636b9c13 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0-mutiny/src/main/java/org/openapitools/client/model/User.java
@@ -274,10 +274,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index ba6816b1ba10..8e4a11ed4bd3 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -136,10 +136,7 @@ public class AdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 2c06d445ecf8..6f27e67e1cca 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -119,10 +119,7 @@ public class AllOfWithSingleRef  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Animal.java
index 94b57aa4949c..fcc4d8107a0a 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Animal.java
@@ -121,10 +121,7 @@ public class Animal  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index e3565fa5e66d..7b744de5dd26 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -105,10 +105,7 @@ public class ArrayOfArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 95e10ceb42c0..c33454927d69 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -105,10 +105,7 @@ public class ArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ArrayTest.java
index 61dae17e29cb..3dcfbcaa7f7a 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -171,10 +171,7 @@ public class ArrayTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Capitalization.java
index 97b7e9656d32..70b30baf20b9 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -221,10 +221,7 @@ public class Capitalization  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Cat.java
index b59be7d7ab4e..ada4d88eadca 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Cat.java
@@ -95,10 +95,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Category.java
index 18c1765ee71f..4607d57fe0bb 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Category.java
@@ -118,10 +118,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 854676c129d3..a5032006247d 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -95,10 +95,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ClassModel.java
index cfe065f5124c..6bd72e0b0cdd 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -96,10 +96,7 @@ public class ClassModel  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Client.java
index 2cb633fcf514..0359db1aa65e 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Client.java
@@ -93,10 +93,7 @@ public class Client  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index e5d277f003da..b7af6eb5ad41 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -93,10 +93,7 @@ public class DeprecatedObject  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Dog.java
index c528bf43f2da..6c8c560bbaeb 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Dog.java
@@ -95,10 +95,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/EnumArrays.java
index 21118acf54b2..ec9ce4c545f7 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -213,10 +213,7 @@ public class EnumArrays  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/EnumTest.java
index dd04b8142d32..9f391820ddde 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -440,10 +440,7 @@ public class EnumTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index 091ad12c7a7b..f6182383a946 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -129,10 +129,7 @@ public class FakeBigDecimalMap200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 712db1e75d3e..4caa82913ecb 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -130,10 +130,7 @@ public class FileSchemaTestClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Foo.java
index 2340eec6e254..251b17ab4db2 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Foo.java
@@ -93,10 +93,7 @@ public class Foo  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index 2b7196e33334..f39f4728352c 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -94,10 +94,7 @@ public class FooGetDefaultResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/FormatTest.java
index 0580ebfbbdbe..f29c3abf481e 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -488,10 +488,7 @@ public class FormatTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index cf4a74a3f14a..93f9a48d1705 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -108,10 +108,7 @@ public class HasOnlyReadOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 8b2977365662..0928d905fab5 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -96,10 +96,7 @@ public class HealthCheckResult  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/MapTest.java
index 59efee6f71f6..6f458072aee4 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/MapTest.java
@@ -244,10 +244,7 @@ public class MapTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 655d464c4f6c..678ae32169c9 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -156,10 +156,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Model200Response.java
index e77e782a2249..685276fa026f 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -121,10 +121,7 @@ public class Model200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 8f50330ca0e5..008a3b259030 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -143,10 +143,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ModelFile.java
index 0139886967cd..5875e7f32bdf 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -99,10 +99,7 @@ public class ModelFile  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ModelList.java
index e29d882390dd..4a94f607e6cf 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ModelList.java
@@ -93,10 +93,7 @@ public class ModelList  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ModelReturn.java
index c1cbeb59cd0d..7c8aec5eff79 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -96,10 +96,7 @@ public class ModelReturn  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Name.java
index 256d7beea90d..cf00b297f430 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Name.java
@@ -161,10 +161,7 @@ public class Name  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/NullableClass.java
index 6c3faf671dc9..545e0fa7e5bd 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -469,10 +469,7 @@ public class NullableClass extends HashMap<String, Object> {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/NumberOnly.java
index 3a07fd86875a..506f783d35e0 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -94,10 +94,7 @@ public class NumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index e6a0a18d2c2c..f8c55dbd4ff7 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -187,10 +187,7 @@ public class ObjectWithDeprecatedFields  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Order.java
index 8f1af029f5ff..fb474d91d8d1 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Order.java
@@ -264,10 +264,7 @@ public class Order  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/OuterComposite.java
index d3c41182152f..9ae6899a07b3 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -144,10 +144,7 @@ public class OuterComposite  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 26c94f92d159..bbdb7c056e55 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -94,10 +94,7 @@ public class OuterObjectWithEnumProperty  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index c720c49a6cd9..23ab78a637b1 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -162,10 +162,7 @@ public class ParentWithNullable  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Pet.java
index dabbeb9369c7..b10d1bb08089 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Pet.java
@@ -286,10 +286,7 @@ public class Pet  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index ff079e73bbf6..6fd18e9b6f50 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -117,10 +117,7 @@ public class ReadOnlyFirst  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/SpecialModelName.java
index be622cc0f223..9af1bf40f603 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -93,10 +93,7 @@ public class SpecialModelName  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Tag.java
index 822054574754..839e419d86b1 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/Tag.java
@@ -118,10 +118,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 2f998a78fd7e..c1cb172f256d 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -141,10 +141,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/User.java
index 517ea0ada24a..318cdc4f6fae 100644
--- a/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/microprofile-rest-client-3.0/src/main/java/org/openapitools/client/model/User.java
@@ -271,10 +271,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/Category.java
index f6986051776c..3010e85800dd 100644
--- a/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/Category.java
@@ -118,10 +118,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 335764879aa6..4e9442f3b801 100644
--- a/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -143,10 +143,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/Order.java
index 13994c33aeda..b16ef3b4d192 100644
--- a/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/Order.java
@@ -264,10 +264,7 @@ public class Order  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/Pet.java
index 6875d2b66b7b..67b02556d125 100644
--- a/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/Pet.java
@@ -286,10 +286,7 @@ public class Pet  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/Tag.java
index c4d8ea1428e0..1e3bdd98faec 100644
--- a/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/Tag.java
@@ -118,10 +118,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/User.java
index 0d74e23b5ed1..dac59c28c273 100644
--- a/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/microprofile-rest-client-mutiny/src/main/java/org/openapitools/client/model/User.java
@@ -271,10 +271,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-outer-enum/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/microprofile-rest-client-outer-enum/src/main/java/org/openapitools/client/model/Cat.java
index e5e20404000a..3e435a1a0a06 100644
--- a/samples/client/petstore/java/microprofile-rest-client-outer-enum/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/microprofile-rest-client-outer-enum/src/main/java/org/openapitools/client/model/Cat.java
@@ -141,10 +141,7 @@ public class Cat  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-outer-enum/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/microprofile-rest-client-outer-enum/src/main/java/org/openapitools/client/model/Dog.java
index 77fe42e654a8..6390a3ab41b9 100644
--- a/samples/client/petstore/java/microprofile-rest-client-outer-enum/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/microprofile-rest-client-outer-enum/src/main/java/org/openapitools/client/model/Dog.java
@@ -141,10 +141,7 @@ public class Dog  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Category.java
index bbc2e617e395..a5d994a97f0c 100644
--- a/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Category.java
@@ -121,10 +121,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 0e34b097d22e..68d0b586a919 100644
--- a/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -146,10 +146,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Order.java
index 439ac6b1e9a1..559326f53c0d 100644
--- a/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Order.java
@@ -267,10 +267,7 @@ public class Order  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Pet.java
index 5b36d5667569..ac698fbe3e55 100644
--- a/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Pet.java
@@ -289,10 +289,7 @@ public class Pet  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Tag.java
index ca7bbc3159cf..4b2b0c3000ea 100644
--- a/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Tag.java
@@ -121,10 +121,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/User.java
index 60a914361519..085d636b9c13 100644
--- a/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter/src/main/java/org/openapitools/client/model/User.java
@@ -274,10 +274,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 6f296140d3ca..c18694510d28 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -133,10 +133,7 @@ public class AdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 59f08cdaa87d..da90ee6234f6 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -116,10 +116,7 @@ public class AllOfWithSingleRef  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Animal.java
index 5f3c15a7922d..02154f0a82ff 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Animal.java
@@ -115,10 +115,7 @@ public class Animal  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index d040d8b3b1cb..f8adad7c2737 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -102,10 +102,7 @@ public class ArrayOfArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index ab044052d515..6fc19f816645 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -102,10 +102,7 @@ public class ArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ArrayTest.java
index f77063ac4d92..aeb7ebc70bf9 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -168,10 +168,7 @@ public class ArrayTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Capitalization.java
index 3f5f3e65fea8..d5a168a1ae19 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -218,10 +218,7 @@ public class Capitalization  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Cat.java
index 03b205a702ac..479a924548d5 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Cat.java
@@ -92,10 +92,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Category.java
index c59e87d82347..7930ea4617e2 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Category.java
@@ -115,10 +115,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 276a0648576a..b89ac6ecca51 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -92,10 +92,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ClassModel.java
index e0892d40a655..207f4fd575af 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -93,10 +93,7 @@ public class ClassModel  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Client.java
index b2b3791b2cb1..54ae5cc8c929 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Client.java
@@ -90,10 +90,7 @@ public class Client  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 1a46d21906a8..3f7a8d6cb5d7 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -90,10 +90,7 @@ public class DeprecatedObject  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Dog.java
index c07f5986d7d2..a3574e34f3c2 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Dog.java
@@ -92,10 +92,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/EnumArrays.java
index c1f21ab594fd..c8963dfd4456 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -210,10 +210,7 @@ public class EnumArrays  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/EnumTest.java
index ecafeb133f92..9dc3193f10a0 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -437,10 +437,7 @@ public class EnumTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index 775976140895..766975b4a9f3 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -126,10 +126,7 @@ public class FakeBigDecimalMap200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 67f9c39481f3..3de277a9035d 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -127,10 +127,7 @@ public class FileSchemaTestClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Foo.java
index 8816b549b1e6..1fa1f49f2866 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Foo.java
@@ -90,10 +90,7 @@ public class Foo  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index 28ad28e94acd..6b2bed53c17b 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -91,10 +91,7 @@ public class FooGetDefaultResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/FormatTest.java
index 40dce2fbdb85..ac0dc78caa54 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -485,10 +485,7 @@ public class FormatTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 6932c8c1b0f7..55dad692f342 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -105,10 +105,7 @@ public class HasOnlyReadOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index a81e2d3cbfc5..10abc855d31d 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -93,10 +93,7 @@ public class HealthCheckResult  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/MapTest.java
index 0a5eee9602dd..d66a1835d609 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/MapTest.java
@@ -241,10 +241,7 @@ public class MapTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index c24f348fb031..23ba5e8d29f0 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -153,10 +153,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Model200Response.java
index ee9b3e3858a2..4449c4180ade 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -118,10 +118,7 @@ public class Model200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 0a251b6c51d2..2a328430e51d 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -140,10 +140,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ModelFile.java
index 25c2612ba1f8..c4559686941a 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -96,10 +96,7 @@ public class ModelFile  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ModelList.java
index 8db3b2d4c35e..fa3e0be4ff7a 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ModelList.java
@@ -90,10 +90,7 @@ public class ModelList  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ModelReturn.java
index c45dc77bffc2..e7902eee8bc0 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -93,10 +93,7 @@ public class ModelReturn  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Name.java
index c653b77ba74b..7ff736e33bfc 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Name.java
@@ -158,10 +158,7 @@ public class Name  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/NullableClass.java
index add6492cb0a0..04cefba09ca6 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -466,10 +466,7 @@ public class NullableClass extends HashMap<String, Object> {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/NumberOnly.java
index f547aaf87a41..127482466ccd 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -91,10 +91,7 @@ public class NumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index ddeb1bf51900..2f8ffc624188 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -184,10 +184,7 @@ public class ObjectWithDeprecatedFields  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Order.java
index fcb4da2f2c33..277d3fff320e 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Order.java
@@ -261,10 +261,7 @@ public class Order  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/OuterComposite.java
index 17a7d7deb4e7..d1b17df9f090 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -141,10 +141,7 @@ public class OuterComposite  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index d13f4da53b7b..8791523aa05c 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -91,10 +91,7 @@ public class OuterObjectWithEnumProperty  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index 7b26de0fa7f6..9d2b608cb0e8 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -157,10 +157,7 @@ public class ParentWithNullable  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Pet.java
index c27bbfdc4a21..4096c62a4a2f 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Pet.java
@@ -283,10 +283,7 @@ public class Pet  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 93f0bbddfbfe..d2e0f7309da2 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -114,10 +114,7 @@ public class ReadOnlyFirst  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/SpecialModelName.java
index 82eefd57b305..af3a680e8499 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -90,10 +90,7 @@ public class SpecialModelName  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Tag.java
index 2bd4f9d28d2f..4381449547af 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/Tag.java
@@ -115,10 +115,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index a911334c8835..1b41982814e4 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -138,10 +138,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/User.java
index 95c977ad0646..2efd9f6bcc8a 100644
--- a/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/microprofile-rest-client/src/main/java/org/openapitools/client/model/User.java
@@ -268,10 +268,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 0698d5760684..367de012e9ec 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -105,10 +105,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 0b9d8f0c7bcd..a7b9528fff31 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -375,10 +375,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
index f6ff96c4da28..5a2c0930a75b 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
@@ -102,10 +102,7 @@ public class AllOfRefToDouble {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
index b20ac3b5c3e0..70680f0c3213 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
@@ -102,10 +102,7 @@ public class AllOfRefToFloat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AllOfRefToLong.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
index ac7bc1c4c420..d6568b0e896a 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
@@ -102,10 +102,7 @@ public class AllOfRefToLong {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Animal.java
index 2c28db9f67e8..e0b2679a4f35 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Animal.java
@@ -147,10 +147,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Apple.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Apple.java
index 4c12fbcb25ca..e2462ce657e4 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Apple.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Apple.java
@@ -133,10 +133,7 @@ public class Apple {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AppleReq.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AppleReq.java
index 0c69d33697a1..84da1eaa547e 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AppleReq.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/AppleReq.java
@@ -133,10 +133,7 @@ public class AppleReq {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 3e01013c06fe..557278c2bc36 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -113,10 +113,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 1a412b401700..848f55204227 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -113,10 +113,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayTest.java
index 0954a48179f2..6e4e78867b85 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -191,10 +191,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Banana.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Banana.java
index edab057d8f14..6cd6ccf2df97 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Banana.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Banana.java
@@ -103,10 +103,7 @@ public class Banana {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/BananaReq.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/BananaReq.java
index 9aa09d08948e..6aba7ce5afb6 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/BananaReq.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/BananaReq.java
@@ -134,10 +134,7 @@ public class BananaReq {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/BasquePig.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/BasquePig.java
index 5db049893990..db46c207eed0 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/BasquePig.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/BasquePig.java
@@ -102,10 +102,7 @@ public class BasquePig {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Capitalization.java
index 07d0195d74c8..c0f660651951 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -257,10 +257,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Cat.java
index 542bf11486c8..59eacf85fd64 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Cat.java
@@ -128,10 +128,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Category.java
index d03dfee22b2d..bffe04e65660 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Category.java
@@ -133,10 +133,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ChildCat.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ChildCat.java
index 2e28a1fa8f3d..f343f9a9c800 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ChildCat.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ChildCat.java
@@ -160,10 +160,7 @@ public class ChildCat extends ParentPet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ClassModel.java
index f0a8e3d44080..e587d6407282 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -102,10 +102,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Client.java
index e6f3820ca47a..a2b3ba7ab4ea 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Client.java
@@ -102,10 +102,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
index 608cf0df56fe..435d10379ca7 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
@@ -133,10 +133,7 @@ public class ComplexQuadrilateral {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DanishPig.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DanishPig.java
index 7f9039e61989..fb09f6dcc616 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DanishPig.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DanishPig.java
@@ -102,10 +102,7 @@ public class DanishPig {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 32d30434bb7b..2eaab8ff18fb 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -104,10 +104,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Dog.java
index 90057ff85830..bdd08444c50b 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Dog.java
@@ -127,10 +127,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Drawing.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Drawing.java
index 3321ea116f26..e51830c8fad2 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Drawing.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Drawing.java
@@ -280,10 +280,7 @@ public class Drawing {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumArrays.java
index 57bd9d7311ce..6d184943916f 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -213,10 +213,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumTest.java
index a5e6547603fb..1491e2d39f2f 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -555,10 +555,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EquilateralTriangle.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
index a676597b2a53..41ada6107142 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
@@ -133,10 +133,7 @@ public class EquilateralTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index f7f28540c319..0c660cc56f2e 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -144,10 +144,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index b9490220d089..fa8f41bb3b9e 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -144,10 +144,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Foo.java
index 9d5d227cc695..5f4b4481d0bd 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Foo.java
@@ -102,10 +102,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index 70c7cacae1ed..173ad57fc0da 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -103,10 +103,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FormatTest.java
index 2010b24bd34b..a57ac3f7cf2b 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -582,10 +582,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/GrandparentAnimal.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
index 35a75d9fdb84..cc946523ce15 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
@@ -116,10 +116,7 @@ public class GrandparentAnimal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index bec3a4e9f87e..b3473ac598fa 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -123,10 +123,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index e0ca3546bcae..f5f20f4f069b 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -124,10 +124,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
index a6deb4b7d8fd..9c99a5c68698 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
@@ -133,10 +133,7 @@ public class IsoscelesTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/MapTest.java
index 3b5b2f25fb99..63dbf9a3a2c8 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/MapTest.java
@@ -264,10 +264,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index d3cc63128244..2c8f9590a98e 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -177,10 +177,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Model200Response.java
index 1d2a296c3396..6301b4270cbe 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -133,10 +133,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index cfe721f5c533..402b2a75b68c 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -164,10 +164,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelFile.java
index 6d487cf01e2c..3e1f3e7c3c0e 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -102,10 +102,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelList.java
index daf11942125b..d151c6d1a052 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelList.java
@@ -102,10 +102,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelReturn.java
index 206d1dd9e8aa..5bda9158bd97 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -102,10 +102,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Name.java
index debcb4a648b6..267e0c69a75d 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Name.java
@@ -185,10 +185,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NullableClass.java
index e0f1d3b940a1..56259e52dc4b 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -648,10 +648,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NumberOnly.java
index 8b288d9170f3..4aa16192d691 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -103,10 +103,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 35e91f4cd0ea..9a754545d72f 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -213,10 +213,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Order.java
index 10f989eb2f6c..7be814d0d6b0 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Order.java
@@ -295,10 +295,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterComposite.java
index 63fa84cb4ea4..f822a2844cd9 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -165,10 +165,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ParentPet.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ParentPet.java
index 2e5c2dcf8a2b..fa33dc838bee 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ParentPet.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ParentPet.java
@@ -92,10 +92,7 @@ public class ParentPet extends GrandparentAnimal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Pet.java
index c1dc55bd87b5..3ef809df0d18 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Pet.java
@@ -314,10 +314,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
index 270fa5343d56..84b41b4eb5d2 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
@@ -102,10 +102,7 @@ public class QuadrilateralInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 3d91568f003b..660320801c31 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -131,10 +131,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ScaleneTriangle.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
index 6e87481ea265..e8fe28e97e9c 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
@@ -133,10 +133,7 @@ public class ScaleneTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ShapeInterface.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ShapeInterface.java
index 25e7d5376ba5..1dfc77fcf301 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ShapeInterface.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ShapeInterface.java
@@ -102,10 +102,7 @@ public class ShapeInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
index 5988aa5c5354..d7bfeb04e307 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
@@ -133,10 +133,7 @@ public class SimpleQuadrilateral {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SpecialModelName.java
index 21102a9de0a5..1cb4f6061fe5 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -133,10 +133,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Tag.java
index f051add41100..2175627109e1 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Tag.java
@@ -133,10 +133,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index fc5fe01252fa..53dc848c85d2 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -151,10 +151,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/TriangleInterface.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/TriangleInterface.java
index f8e797b060e5..2663baa03b57 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/TriangleInterface.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/TriangleInterface.java
@@ -102,10 +102,7 @@ public class TriangleInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/User.java
index aa7cc4bd76b3..36f6d43d1e74 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/User.java
@@ -479,10 +479,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Whale.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Whale.java
index 4b5bee7974bc..92e3f06a6713 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Whale.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Whale.java
@@ -164,10 +164,7 @@ public class Whale {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Zebra.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Zebra.java
index 1d3fa36a74d6..4322285337cb 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Zebra.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Zebra.java
@@ -219,10 +219,7 @@ public class Zebra {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 0698d5760684..367de012e9ec 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -105,10 +105,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 2fcb24e16539..68c4b10fcb2a 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -340,10 +340,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
index 09825cb3bfd7..2fb51a20d7a2 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
@@ -96,10 +96,7 @@ public class AllOfRefToDouble {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
index 37bf2e22ac92..0e8576669f01 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
@@ -96,10 +96,7 @@ public class AllOfRefToFloat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AllOfRefToLong.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
index 8a614037e481..b38dfedda9ab 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
@@ -96,10 +96,7 @@ public class AllOfRefToLong {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Animal.java
index 301cf24c3593..74ca875dd2a6 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Animal.java
@@ -140,10 +140,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Apple.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Apple.java
index dbbd33c7898a..ff36960eb0c0 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Apple.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Apple.java
@@ -127,10 +127,7 @@ public class Apple {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AppleReq.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AppleReq.java
index d90f5c7d5af2..ccb5a3af0a76 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AppleReq.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/AppleReq.java
@@ -127,10 +127,7 @@ public class AppleReq {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 762475a38eb2..f6f6ae2f9738 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index a7c79aaf124b..f15f8fda0358 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ArrayTest.java
index 715c306dc29b..7a3503ed18bc 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -183,10 +183,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Banana.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Banana.java
index 1390e42eb804..d360d82710e7 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Banana.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Banana.java
@@ -98,10 +98,7 @@ public class Banana {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/BananaReq.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/BananaReq.java
index 35b7f3b44338..30fdc2dc314b 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/BananaReq.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/BananaReq.java
@@ -128,10 +128,7 @@ public class BananaReq {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/BasquePig.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/BasquePig.java
index 8a570e00ea43..4c636100f9af 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/BasquePig.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/BasquePig.java
@@ -96,10 +96,7 @@ public class BasquePig {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Capitalization.java
index 56ebd404304e..42542d74aeee 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -246,10 +246,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Cat.java
index 63e9d62d3c71..1d590383b20e 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Cat.java
@@ -121,10 +121,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Category.java
index 082cfd5aaf16..e60b3e4be8a0 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Category.java
@@ -126,10 +126,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ChildCat.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ChildCat.java
index 7925326fcfb4..0b3a3cdf6738 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ChildCat.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ChildCat.java
@@ -152,10 +152,7 @@ public class ChildCat extends ParentPet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ClassModel.java
index 7feca83cc3ad..eb79d2a2263a 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -96,10 +96,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Client.java
index a9b555ac1f11..f59d7b711a30 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Client.java
@@ -96,10 +96,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
index ee011df2877c..07a8e545117e 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
@@ -126,10 +126,7 @@ public class ComplexQuadrilateral {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/DanishPig.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/DanishPig.java
index a806e8383b05..a1d9fdb0b143 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/DanishPig.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/DanishPig.java
@@ -96,10 +96,7 @@ public class DanishPig {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 47585995b147..8f634255b923 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -98,10 +98,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Dog.java
index fdd74a69bbd7..e0317553464e 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Dog.java
@@ -120,10 +120,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Drawing.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Drawing.java
index 0d9e62938f12..fabd1fa0924a 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Drawing.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Drawing.java
@@ -248,10 +248,7 @@ public class Drawing {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/EnumArrays.java
index 300dda69615f..0cc1f101a468 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -206,10 +206,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/EnumTest.java
index 2bd4adfe73d6..a720dd0b318f 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -520,10 +520,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/EquilateralTriangle.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
index 136ca5ef30bf..9c763e1b7991 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
@@ -126,10 +126,7 @@ public class EquilateralTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index c08b2aa4eaad..1ffcdda97259 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -138,10 +138,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index a0cbf388ea6b..4b72b335f8a3 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -137,10 +137,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Foo.java
index 31fecb123894..72ee89abe522 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Foo.java
@@ -96,10 +96,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index fb0a2805a66d..7c1703b10d94 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -98,10 +98,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/FormatTest.java
index 98fb126f343a..21b9e204265e 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -562,10 +562,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/GrandparentAnimal.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
index 160ad2789239..04c2e262a607 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
@@ -110,10 +110,7 @@ public class GrandparentAnimal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 2c86c78e99f3..4e768f8432d9 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -117,10 +117,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index f1ed674d0fbf..2fe805a5438e 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -96,10 +96,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
index 56c65661af74..62d7bfdef01d 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
@@ -126,10 +126,7 @@ public class IsoscelesTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/MapTest.java
index 74e61ef6b9d6..bde6e13344c6 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/MapTest.java
@@ -255,10 +255,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 4dd9d883ec5c..219e15f66273 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -169,10 +169,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Model200Response.java
index 33f7a63fa2c1..31d95478aca0 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -127,10 +127,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 8d4088ac1cde..dce827aa3955 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -157,10 +157,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ModelFile.java
index f8778237598a..562a3fb53d30 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -97,10 +97,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ModelList.java
index 8d71e5146952..35f2f417554f 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ModelList.java
@@ -97,10 +97,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ModelReturn.java
index 878f5890db60..5a9d4a8521c2 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -97,10 +97,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Name.java
index aee889f9d51d..8ce783e5a0e8 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Name.java
@@ -176,10 +176,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/NullableClass.java
index 94aeb545e1eb..6c3daf263c81 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -529,10 +529,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/NumberOnly.java
index 70ec5ef02a81..fbc8f6af4dfc 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -97,10 +97,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index a49ad05365ed..91708395794c 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -204,10 +204,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Order.java
index cfd55ebf435c..81cf0360bee4 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Order.java
@@ -284,10 +284,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/OuterComposite.java
index d90c52e1ad7a..354bc44f00de 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -157,10 +157,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ParentPet.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ParentPet.java
index 627260c0f6d6..5aa42cacb6cc 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ParentPet.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ParentPet.java
@@ -87,10 +87,7 @@ public class ParentPet extends GrandparentAnimal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Pet.java
index 063bb6a3adff..7f7d32072477 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Pet.java
@@ -303,10 +303,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
index 7814d7a1855b..68abb9d4347a 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
@@ -96,10 +96,7 @@ public class QuadrilateralInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 5f52b0e33bf6..08afed2350d9 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -124,10 +124,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ScaleneTriangle.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
index 21a11ea073cb..3d8642078d06 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
@@ -126,10 +126,7 @@ public class ScaleneTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ShapeInterface.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ShapeInterface.java
index 104edd61f15f..970c93248c64 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ShapeInterface.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/ShapeInterface.java
@@ -96,10 +96,7 @@ public class ShapeInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
index af2a5e419311..ba268c0d7c18 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
@@ -126,10 +126,7 @@ public class SimpleQuadrilateral {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/SpecialModelName.java
index f948bb3f9176..6e20e7911708 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -127,10 +127,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Tag.java
index 1a026df0856b..6292c951b8a5 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Tag.java
@@ -126,10 +126,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 70e8127bbbf7..a3a06b6bdf2c 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -145,10 +145,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/TriangleInterface.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/TriangleInterface.java
index ab9db8af9a17..39a1383d7eed 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/TriangleInterface.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/TriangleInterface.java
@@ -96,10 +96,7 @@ public class TriangleInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/User.java
index d3cb9d4aab9c..b8735a300f0a 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/User.java
@@ -426,10 +426,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Whale.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Whale.java
index e72e4a3de003..f1dcff64629d 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Whale.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Whale.java
@@ -157,10 +157,7 @@ public class Whale {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Zebra.java b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Zebra.java
index 8b4808d4ebd4..39c9f836fb33 100644
--- a/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Zebra.java
+++ b/samples/client/petstore/java/native-jackson3/src/main/java/org/openapitools/client/model/Zebra.java
@@ -212,10 +212,7 @@ public class Zebra {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 2e7f54df70ad..b829626e0aec 100644
--- a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -105,10 +105,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Category.java
index 0320666da10a..6374fc3facab 100644
--- a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Category.java
@@ -133,10 +133,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index fb12a048bddc..4ed8d2612475 100644
--- a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -164,10 +164,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Order.java
index fa4199cf2696..70c10084add1 100644
--- a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Order.java
@@ -295,10 +295,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Pet.java
index 7a9f3b067aeb..d3a027da28f8 100644
--- a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Pet.java
@@ -316,10 +316,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Tag.java
index 7e76b6418a01..b23feceb9427 100644
--- a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Tag.java
@@ -133,10 +133,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/User.java
index c586fee67c09..3f7a0266febb 100644
--- a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/User.java
@@ -319,10 +319,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-useGzipFeature/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/native-useGzipFeature/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 2e7f54df70ad..b829626e0aec 100644
--- a/samples/client/petstore/java/native-useGzipFeature/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/native-useGzipFeature/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -105,10 +105,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/native-useGzipFeature/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/native-useGzipFeature/src/main/java/org/openapitools/client/model/Category.java
index 0320666da10a..6374fc3facab 100644
--- a/samples/client/petstore/java/native-useGzipFeature/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/native-useGzipFeature/src/main/java/org/openapitools/client/model/Category.java
@@ -133,10 +133,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-useGzipFeature/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/native-useGzipFeature/src/main/java/org/openapitools/client/model/Pet.java
index 7a9f3b067aeb..d3a027da28f8 100644
--- a/samples/client/petstore/java/native-useGzipFeature/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/native-useGzipFeature/src/main/java/org/openapitools/client/model/Pet.java
@@ -316,10 +316,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native-useGzipFeature/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/native-useGzipFeature/src/main/java/org/openapitools/client/model/Tag.java
index 7e76b6418a01..b23feceb9427 100644
--- a/samples/client/petstore/java/native-useGzipFeature/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/native-useGzipFeature/src/main/java/org/openapitools/client/model/Tag.java
@@ -133,10 +133,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 0698d5760684..367de012e9ec 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -105,10 +105,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 2b31f0d129b9..d4096df11546 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -363,10 +363,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
index 87db4cf60223..cfee4db3db4b 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
@@ -97,10 +97,7 @@ public class AllOfRefToDouble {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
index 4159824f28b8..6acef420d730 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
@@ -97,10 +97,7 @@ public class AllOfRefToFloat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AllOfRefToLong.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
index f4086fa632f3..aceadbf6e427 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
@@ -97,10 +97,7 @@ public class AllOfRefToLong {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Animal.java
index c1de02eebb58..866c66065683 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Animal.java
@@ -141,10 +141,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Apple.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Apple.java
index dbbd33c7898a..ff36960eb0c0 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Apple.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Apple.java
@@ -127,10 +127,7 @@ public class Apple {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AppleReq.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AppleReq.java
index d90f5c7d5af2..ccb5a3af0a76 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AppleReq.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/AppleReq.java
@@ -127,10 +127,7 @@ public class AppleReq {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 4e8aed59c15c..8491f034fc78 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -108,10 +108,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 64f879c47f14..9b21aa9d90b6 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -108,10 +108,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayTest.java
index 06a7f1a88f90..0cd2021ceac4 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -184,10 +184,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Banana.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Banana.java
index 1390e42eb804..d360d82710e7 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Banana.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Banana.java
@@ -98,10 +98,7 @@ public class Banana {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/BananaReq.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/BananaReq.java
index 35b7f3b44338..30fdc2dc314b 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/BananaReq.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/BananaReq.java
@@ -128,10 +128,7 @@ public class BananaReq {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/BasquePig.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/BasquePig.java
index b5bc6f7775f6..c67d9493287f 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/BasquePig.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/BasquePig.java
@@ -97,10 +97,7 @@ public class BasquePig {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Capitalization.java
index 9533e5ef2fc0..a4679f3377c2 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -247,10 +247,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Cat.java
index b4d63cf954ec..a84a2b3acfce 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Cat.java
@@ -122,10 +122,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Category.java
index 506b65c1b1bc..c88e6e885c3a 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Category.java
@@ -127,10 +127,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ChildCat.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ChildCat.java
index 1dc37b473174..2eae2ae99f33 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ChildCat.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ChildCat.java
@@ -153,10 +153,7 @@ public class ChildCat extends ParentPet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ClassModel.java
index b90db5e44645..8f82eb130f5b 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -97,10 +97,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Client.java
index 77bbb7003ea0..dd4528884584 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Client.java
@@ -97,10 +97,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
index aec838853ea0..3fef8c24d2e3 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
@@ -127,10 +127,7 @@ public class ComplexQuadrilateral {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/DanishPig.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/DanishPig.java
index 52a025f9ee32..a1349df1ba74 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/DanishPig.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/DanishPig.java
@@ -97,10 +97,7 @@ public class DanishPig {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index c421abfa4d1a..d03a82cc2d7d 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -99,10 +99,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Dog.java
index e1804768b7be..f9926754eb34 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Dog.java
@@ -121,10 +121,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Drawing.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Drawing.java
index ede0e11e0494..846e8960500d 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Drawing.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Drawing.java
@@ -271,10 +271,7 @@ public class Drawing {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumArrays.java
index 64c32c2581a7..adda5b87d0a4 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -207,10 +207,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumTest.java
index 7ee8daec3175..ffab91e95e86 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -542,10 +542,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EquilateralTriangle.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
index fd5f3ca43816..f72174339d9d 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
@@ -127,10 +127,7 @@ public class EquilateralTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index c08b2aa4eaad..1ffcdda97259 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -138,10 +138,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index be23ad63f7a6..5eb849165964 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -138,10 +138,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Foo.java
index 4da52339463a..5722d6a58f27 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Foo.java
@@ -97,10 +97,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index fb0a2805a66d..7c1703b10d94 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -98,10 +98,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FormatTest.java
index 98fb126f343a..21b9e204265e 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -562,10 +562,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/GrandparentAnimal.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
index 7f221420d99d..f6a7d1d78d91 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
@@ -111,10 +111,7 @@ public class GrandparentAnimal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 2c86c78e99f3..4e768f8432d9 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -117,10 +117,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 25f885339087..d6654375e144 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -119,10 +119,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
index 020f3970943e..c7f21e4272a4 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
@@ -127,10 +127,7 @@ public class IsoscelesTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/MapTest.java
index e1c3390f206e..e4b3c6cf76cb 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/MapTest.java
@@ -256,10 +256,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index ad771b309057..811612a2c6fa 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -170,10 +170,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Model200Response.java
index 33f7a63fa2c1..31d95478aca0 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -127,10 +127,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 8d4088ac1cde..dce827aa3955 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -157,10 +157,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelFile.java
index f8778237598a..562a3fb53d30 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -97,10 +97,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelList.java
index 8d71e5146952..35f2f417554f 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelList.java
@@ -97,10 +97,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelReturn.java
index 878f5890db60..5a9d4a8521c2 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -97,10 +97,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Name.java
index 3fdecf6fb353..4cf7f038128f 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Name.java
@@ -177,10 +177,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableClass.java
index 4c8ebb0a595c..5ca5cd156df3 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -631,10 +631,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NumberOnly.java
index 0410b7b2cae2..84ab8e56e552 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -98,10 +98,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 5bab96a21742..d5ff282c9a51 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -205,10 +205,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Order.java
index 20e8b5ddbbee..2961dd44e17f 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Order.java
@@ -285,10 +285,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterComposite.java
index 8f5623dfb275..0f2b26c7fa21 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -158,10 +158,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ParentPet.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ParentPet.java
index 6b92af76761b..0bfa2205d5aa 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ParentPet.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ParentPet.java
@@ -88,10 +88,7 @@ public class ParentPet extends GrandparentAnimal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Pet.java
index d924329e6900..c0cdd79a8444 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Pet.java
@@ -304,10 +304,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
index 1c47be77c907..88347a9a1a17 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
@@ -97,10 +97,7 @@ public class QuadrilateralInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 7c436cb400cd..925f97e8db30 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -125,10 +125,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ScaleneTriangle.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
index 39bfeb27239c..bae21b42c3b8 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
@@ -127,10 +127,7 @@ public class ScaleneTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ShapeInterface.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ShapeInterface.java
index 2039b965b374..abd5bacd7883 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ShapeInterface.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ShapeInterface.java
@@ -97,10 +97,7 @@ public class ShapeInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
index 397edad8ae0f..ed3c5670a920 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
@@ -127,10 +127,7 @@ public class SimpleQuadrilateral {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/SpecialModelName.java
index f948bb3f9176..6e20e7911708 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -127,10 +127,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Tag.java
index 6ef417202e61..e5fe5f560626 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Tag.java
@@ -127,10 +127,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 70e8127bbbf7..a3a06b6bdf2c 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -145,10 +145,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/TriangleInterface.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/TriangleInterface.java
index 073285644bdb..229253eff7fb 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/TriangleInterface.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/TriangleInterface.java
@@ -97,10 +97,7 @@ public class TriangleInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/User.java
index faa288e5237d..8ce406080909 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/User.java
@@ -463,10 +463,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Whale.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Whale.java
index e72e4a3de003..f1dcff64629d 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Whale.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Whale.java
@@ -157,10 +157,7 @@ public class Whale {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Zebra.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Zebra.java
index 8b4808d4ebd4..39c9f836fb33 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Zebra.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Zebra.java
@@ -212,10 +212,7 @@ public class Zebra {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   /**
diff --git a/samples/client/petstore/java/okhttp-gson-3.1-duplicated-operationid/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/okhttp-gson-3.1-duplicated-operationid/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index b7b4e2cb1cbd..e7311fcf9dec 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1-duplicated-operationid/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1-duplicated-operationid/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -104,10 +104,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index b7b4e2cb1cbd..e7311fcf9dec 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -104,10 +104,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AllOfSimpleModel.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AllOfSimpleModel.java
index 57ed892ea7f0..23718d024e60 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AllOfSimpleModel.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AllOfSimpleModel.java
@@ -165,10 +165,7 @@ public class AllOfSimpleModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Animal.java
index 0c16604c5623..1ad0f11352f8 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Animal.java
@@ -182,10 +182,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AnyTypeTest.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AnyTypeTest.java
index 6f9266b6e9e0..279242db2c02 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AnyTypeTest.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AnyTypeTest.java
@@ -237,10 +237,7 @@ public class AnyTypeTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/ArrayOfSameRef.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/ArrayOfSameRef.java
index a52df3d62033..999aaf07f865 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/ArrayOfSameRef.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/ArrayOfSameRef.java
@@ -234,10 +234,7 @@ public class ArrayOfSameRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Cat.java
index 6456bba9d7dc..14663e7325a1 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Cat.java
@@ -159,10 +159,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Category.java
index 4e089c9405fe..b23e9a699da2 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Category.java
@@ -181,10 +181,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/CircularReference1.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/CircularReference1.java
index 80e8e3ed0dd3..5f72efedbaa9 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/CircularReference1.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/CircularReference1.java
@@ -156,10 +156,7 @@ public class CircularReference1 {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/CircularReference2.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/CircularReference2.java
index 5b08e04d0e61..80dfe903afc7 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/CircularReference2.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/CircularReference2.java
@@ -156,10 +156,7 @@ public class CircularReference2 {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/CircularReference3.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/CircularReference3.java
index ae8313568694..41ed85b778e4 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/CircularReference3.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/CircularReference3.java
@@ -156,10 +156,7 @@ public class CircularReference3 {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Dog.java
index 98976d5bbe8e..5b1861ef8e4a 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Dog.java
@@ -159,10 +159,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/FakeWebhooksSourcesDeletedPostRequest.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/FakeWebhooksSourcesDeletedPostRequest.java
index 0727713ac782..17097d28e91c 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/FakeWebhooksSourcesDeletedPostRequest.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/FakeWebhooksSourcesDeletedPostRequest.java
@@ -209,10 +209,7 @@ public class FakeWebhooksSourcesDeletedPostRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/FakeWebhooksSourcesDeletedPostRequestEvent.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/FakeWebhooksSourcesDeletedPostRequestEvent.java
index 8e207dde9849..1e354253a729 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/FakeWebhooksSourcesDeletedPostRequestEvent.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/FakeWebhooksSourcesDeletedPostRequestEvent.java
@@ -155,10 +155,7 @@ public class FakeWebhooksSourcesDeletedPostRequestEvent {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 593f27a0c1f5..20460d977731 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -207,10 +207,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Order.java
index af57db6cbdb8..f0477872a839 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Order.java
@@ -340,10 +340,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Pet.java
index 2cd0cd6c3233..4c4a5c8f7d67 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Pet.java
@@ -364,10 +364,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/PetWithTypesObjectNullAndRef.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/PetWithTypesObjectNullAndRef.java
index 894a300734c9..14b7f93b015d 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/PetWithTypesObjectNullAndRef.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/PetWithTypesObjectNullAndRef.java
@@ -156,10 +156,7 @@ public class PetWithTypesObjectNullAndRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/SelfReferenceAdditionalProperties.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/SelfReferenceAdditionalProperties.java
index 297bf43d74ea..a260f34621cd 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/SelfReferenceAdditionalProperties.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/SelfReferenceAdditionalProperties.java
@@ -155,10 +155,7 @@ public class SelfReferenceAdditionalProperties {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/SimpleModelWithArrayProperty.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/SimpleModelWithArrayProperty.java
index 85a09e2430c6..02a4b36c2a27 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/SimpleModelWithArrayProperty.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/SimpleModelWithArrayProperty.java
@@ -165,10 +165,7 @@ public class SimpleModelWithArrayProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Tag.java
index fb60a2351b4f..20903ecb520e 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Tag.java
@@ -181,10 +181,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/User.java
index cdf7676aab0b..39967a56bd8a 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/User.java
@@ -337,10 +337,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index b7b4e2cb1cbd..e7311fcf9dec 100644
--- a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -104,10 +104,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Category.java
index 4e089c9405fe..b23e9a699da2 100644
--- a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Category.java
@@ -181,10 +181,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 593f27a0c1f5..20460d977731 100644
--- a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -207,10 +207,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Order.java
index af57db6cbdb8..f0477872a839 100644
--- a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Order.java
@@ -340,10 +340,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Pet.java
index 2cd0cd6c3233..4c4a5c8f7d67 100644
--- a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Pet.java
@@ -364,10 +364,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Tag.java
index fb60a2351b4f..20903ecb520e 100644
--- a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Tag.java
@@ -181,10 +181,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/User.java
index cdf7676aab0b..39967a56bd8a 100644
--- a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/User.java
@@ -337,10 +337,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index c46b903bea12..c9bab6e5ad93 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -104,10 +104,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
index 53cd161ef2cc..da78cbc7dc2d 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
@@ -155,10 +155,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
index ec09f5420537..9b3193ea65f2 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
@@ -156,10 +156,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
index ca5ecaa891ec..b785971c0024 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
@@ -155,10 +155,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index fb37ec0d208c..89ec2155f8c2 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -437,10 +437,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
index 0713af528ef0..e511cd3c077d 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
@@ -155,10 +155,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
index 46a10c4123cf..c23832a9f180 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
@@ -156,10 +156,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
index 102a1861629e..5082b9f43b98 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
@@ -156,10 +156,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
index 2b9a7041b923..1535c454efae 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
@@ -155,10 +155,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Animal.java
index ee54266145b2..4a8837a000bf 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Animal.java
@@ -136,10 +136,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 5c8cee642ce9..5e670dbdf7b7 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -120,10 +120,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 565a7122d77a..b24cd2439425 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -120,10 +120,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayTest.java
index 3cee5b5c1b99..198399dc6f78 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -188,10 +188,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/BigCat.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/BigCat.java
index e4056d29df22..e23a8e8f45a2 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/BigCat.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/BigCat.java
@@ -169,10 +169,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Capitalization.java
index 5ceb3ae7ec3d..f93784f7e4f3 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -239,10 +239,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Cat.java
index 2997414b3859..2b7f17aeeaef 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Cat.java
@@ -113,10 +113,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Category.java
index c43288db310f..bd5fe4dfadc1 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Category.java
@@ -135,10 +135,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ClassModel.java
index e2ac57852ef7..815325e427e7 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -109,10 +109,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Client.java
index 037c347cf008..5bc7335b231b 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Client.java
@@ -109,10 +109,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Dog.java
index 6f1d88d2a043..6411a5884938 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Dog.java
@@ -113,10 +113,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/EnumArrays.java
index 440237dae751..eea6c3dd04a3 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -249,10 +249,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/EnumTest.java
index ccb2be14c51c..7385f2fabe98 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -426,10 +426,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 91b57bcfd2a3..18b61e6325e9 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -146,10 +146,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/FormatTest.java
index 49fbfeb4ec6d..246a6dad4fe6 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -462,10 +462,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 03f1d2f8acf1..98b9a72fe3a9 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -128,10 +128,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/MapTest.java
index 4e5ef82a54ce..359f2ff8fc3c 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/MapTest.java
@@ -273,10 +273,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 297568bd8527..da16d7910793 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -174,10 +174,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Model200Response.java
index fcf62323d7c5..ba765bd90291 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -135,10 +135,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 697f098a586f..994a8a87c0db 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -161,10 +161,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ModelFile.java
index 16809b9cf754..5ac14d12be36 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -109,10 +109,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ModelList.java
index c1937873a213..44b3a0b8b404 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ModelList.java
@@ -109,10 +109,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ModelReturn.java
index 2a5364400a2a..d8cbeafb8be4 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -109,10 +109,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Name.java
index 9527d25fadb6..c7e937ca2887 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Name.java
@@ -180,10 +180,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/NumberOnly.java
index d1fe6c2e0829..00ed88cad121 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -110,10 +110,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Order.java
index 5763bb18143a..3f2df4c0ffc3 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Order.java
@@ -294,10 +294,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/OuterComposite.java
index 949be321e39f..fdf9323eeb48 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -162,10 +162,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Pet.java
index d21fc66b3ffb..84f58e2e87be 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Pet.java
@@ -315,10 +315,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index de5a7e39a605..4c4ee17c76db 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -134,10 +134,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/SpecialModelName.java
index c94d52a5048e..c8e0a05053e9 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -109,10 +109,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Tag.java
index 200a9595ace4..a451329c243d 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Tag.java
@@ -135,10 +135,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/TypeHolderDefault.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
index 4f67d56607b3..941747c6779b 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
@@ -224,10 +224,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/TypeHolderExample.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/TypeHolderExample.java
index be63f3a4bc44..96932e93a4b2 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/TypeHolderExample.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/TypeHolderExample.java
@@ -250,10 +250,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/User.java
index 115e5bb871c0..ff602952d619 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/User.java
@@ -291,10 +291,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/XmlItem.java
index f86610363e53..7be2ccfe55a9 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -912,10 +912,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index b7b4e2cb1cbd..e7311fcf9dec 100644
--- a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -104,10 +104,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Category.java
index 4e089c9405fe..b23e9a699da2 100644
--- a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Category.java
@@ -181,10 +181,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 593f27a0c1f5..20460d977731 100644
--- a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -207,10 +207,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Order.java
index af57db6cbdb8..f0477872a839 100644
--- a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Order.java
@@ -340,10 +340,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Pet.java
index 2cd0cd6c3233..4c4a5c8f7d67 100644
--- a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Pet.java
@@ -364,10 +364,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Tag.java
index fb60a2351b4f..20903ecb520e 100644
--- a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Tag.java
@@ -181,10 +181,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/User.java
index cdf7676aab0b..39967a56bd8a 100644
--- a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/User.java
@@ -337,10 +337,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index b7b4e2cb1cbd..e7311fcf9dec 100644
--- a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -104,10 +104,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Category.java
index 4e089c9405fe..b23e9a699da2 100644
--- a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Category.java
@@ -181,10 +181,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 593f27a0c1f5..20460d977731 100644
--- a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -207,10 +207,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Order.java
index af57db6cbdb8..f0477872a839 100644
--- a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Order.java
@@ -340,10 +340,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Pet.java
index 2cd0cd6c3233..4c4a5c8f7d67 100644
--- a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Pet.java
@@ -364,10 +364,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/PetWithRequiredNullableCases1.java b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/PetWithRequiredNullableCases1.java
index e6157a569986..e963f251b89c 100644
--- a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/PetWithRequiredNullableCases1.java
+++ b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/PetWithRequiredNullableCases1.java
@@ -376,10 +376,7 @@ public class PetWithRequiredNullableCases1 {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/PetWithRequiredNullableCases2.java b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/PetWithRequiredNullableCases2.java
index 23f1a64b8656..2b3e6db27f47 100644
--- a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/PetWithRequiredNullableCases2.java
+++ b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/PetWithRequiredNullableCases2.java
@@ -364,10 +364,7 @@ public class PetWithRequiredNullableCases2 {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Tag.java
index fb60a2351b4f..20903ecb520e 100644
--- a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Tag.java
@@ -181,10 +181,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/User.java
index cdf7676aab0b..39967a56bd8a 100644
--- a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/User.java
@@ -337,10 +337,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index c46b903bea12..c9bab6e5ad93 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -104,10 +104,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
index da1e6f3910a1..02955a853b44 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
@@ -157,10 +157,7 @@ public class AdditionalPropertiesAnyType implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
index feb749a5bec0..ee73e7634b54 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
@@ -158,10 +158,7 @@ public class AdditionalPropertiesArray implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
index 94a285e6b6f4..3d2acdc5d387 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
@@ -157,10 +157,7 @@ public class AdditionalPropertiesBoolean implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 890db8222dae..95e7e9198cde 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -439,10 +439,7 @@ public class AdditionalPropertiesClass implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
index 6caffe0f769c..b5cd44a4a7ae 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
@@ -157,10 +157,7 @@ public class AdditionalPropertiesInteger implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
index 9fb5f20d9acb..3cd44c36b587 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
@@ -158,10 +158,7 @@ public class AdditionalPropertiesNumber implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
index 24ad0952f6b9..986523d228b8 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
@@ -158,10 +158,7 @@ public class AdditionalPropertiesObject implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
index a88ec9af6cb7..7669e06cdb3b 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
@@ -157,10 +157,7 @@ public class AdditionalPropertiesString implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Animal.java
index 4f26b4843cc9..2d89bed4b14f 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Animal.java
@@ -138,10 +138,7 @@ public class Animal implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 3bdfd99bec2d..b133966fd817 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -122,10 +122,7 @@ public class ArrayOfArrayOfNumberOnly implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 185c337c4590..93d47c65b541 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -122,10 +122,7 @@ public class ArrayOfNumberOnly implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayTest.java
index df1292069de3..50c3a8fe4ed0 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -190,10 +190,7 @@ public class ArrayTest implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/BigCat.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/BigCat.java
index c69300cae8ed..f0afc6dc379b 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/BigCat.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/BigCat.java
@@ -172,10 +172,7 @@ public class BigCat extends Cat implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Capitalization.java
index ea99bf68dc80..28eae56b3b4f 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -241,10 +241,7 @@ public class Capitalization implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Cat.java
index af62c95be965..51919928f44e 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Cat.java
@@ -116,10 +116,7 @@ public class Cat extends Animal implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Category.java
index edc6fc81d537..b11b769f2bd1 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Category.java
@@ -137,10 +137,7 @@ public class Category implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ClassModel.java
index 938e31f072e6..f84707242628 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -111,10 +111,7 @@ public class ClassModel implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Client.java
index 6557264699b5..3fe61289bedf 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Client.java
@@ -111,10 +111,7 @@ public class Client implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Dog.java
index 5b583bc1ea7f..b244c8e22c4b 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Dog.java
@@ -116,10 +116,7 @@ public class Dog extends Animal implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/EnumArrays.java
index 72c42950ee56..d2431c5ed27b 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -251,10 +251,7 @@ public class EnumArrays implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/EnumTest.java
index 0dcc6a67efa0..41dbd0b22683 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -428,10 +428,7 @@ public class EnumTest implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 33fc79621c36..0ca179b8c6f2 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -148,10 +148,7 @@ public class FileSchemaTestClass implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/FormatTest.java
index 31d1c586e812..05d0391616d0 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -464,10 +464,7 @@ public class FormatTest implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 5aac072dd7d5..b490ea33b4f7 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -130,10 +130,7 @@ public class HasOnlyReadOnly implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/MapTest.java
index 5fed26afb122..f9863fbd61ff 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/MapTest.java
@@ -275,10 +275,7 @@ public class MapTest implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index edcfeb8206ab..597336fb6a0d 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -176,10 +176,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Model200Response.java
index 4e5817bbbbaf..9efb0c320754 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -137,10 +137,7 @@ public class Model200Response implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 1629d322a2f2..8a954befcd40 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -163,10 +163,7 @@ public class ModelApiResponse implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ModelFile.java
index 406c22024592..d10cc7da560a 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -111,10 +111,7 @@ public class ModelFile implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ModelList.java
index aa8bdb456867..6b48d0634006 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ModelList.java
@@ -111,10 +111,7 @@ public class ModelList implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ModelReturn.java
index 4fc0ae5010cc..5a651c148dbb 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -111,10 +111,7 @@ public class ModelReturn implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Name.java
index 02de009c1b6b..fe590f9b2eaa 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Name.java
@@ -182,10 +182,7 @@ public class Name implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/NumberOnly.java
index 3d3d08de7f43..4e18cec4241c 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -112,10 +112,7 @@ public class NumberOnly implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Order.java
index 685e5274552c..be14d4aaa462 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Order.java
@@ -296,10 +296,7 @@ public class Order implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/OuterComposite.java
index c2ab0ebeb4b2..f015e0af533c 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -164,10 +164,7 @@ public class OuterComposite implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Pet.java
index 03dd284eaba1..247f5d6bbcab 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Pet.java
@@ -317,10 +317,7 @@ public class Pet implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index b5808f9daada..0da54e3fb874 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -136,10 +136,7 @@ public class ReadOnlyFirst implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/SpecialModelName.java
index 5e5b8547c6d1..8dfd44f2af86 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -111,10 +111,7 @@ public class SpecialModelName implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Tag.java
index 710b2f9a149c..2fd342a16058 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Tag.java
@@ -137,10 +137,7 @@ public class Tag implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/TypeHolderDefault.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
index f932cc861d89..cf3c9265facf 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
@@ -226,10 +226,7 @@ public class TypeHolderDefault implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/TypeHolderExample.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/TypeHolderExample.java
index 971ac539c582..75ef9331d8d0 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/TypeHolderExample.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/TypeHolderExample.java
@@ -252,10 +252,7 @@ public class TypeHolderExample implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/User.java
index 8d8e7656665b..bc4376b908c4 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/User.java
@@ -293,10 +293,7 @@ public class User implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/XmlItem.java
index f7bb5b6d50ea..b02c414e0151 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -914,10 +914,7 @@ public class XmlItem implements Parcelable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index b7b4e2cb1cbd..e7311fcf9dec 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -104,10 +104,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Category.java
index 9f5ac0c2720e..1e77e4f65f61 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Category.java
@@ -186,10 +186,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 4fc36dc63717..672af7abf370 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -213,10 +213,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Order.java
index 8c11af2a1883..b1a54aaed2fb 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Order.java
@@ -349,10 +349,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Pet.java
index 8e5895fe476c..fc8bb8efedb0 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Pet.java
@@ -373,10 +373,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Tag.java
index c4169aeed541..72b359ec86e0 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Tag.java
@@ -186,10 +186,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/User.java
index d5b05537bf79..c8b7c752a625 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/User.java
@@ -348,10 +348,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index b7b4e2cb1cbd..e7311fcf9dec 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -104,10 +104,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Category.java
index 0d732a0d7dd3..7a7557783bf7 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Category.java
@@ -185,10 +185,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 8157ab525969..c3b67894558e 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -212,10 +212,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Order.java
index 5bffe1262d70..8f02a74beadb 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Order.java
@@ -348,10 +348,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Pet.java
index 747ab2060db0..61b4653c6527 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Pet.java
@@ -372,10 +372,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Tag.java
index 0e401f7c6e1d..500ba31859c1 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Tag.java
@@ -185,10 +185,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/User.java
index aecd8592e51b..4dadd87d01fc 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/User.java
@@ -347,10 +347,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index c46b903bea12..c9bab6e5ad93 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -104,10 +104,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 29df5d4e11a4..d365b3dd93b1 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -383,10 +383,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfModelArrayAnyOf.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfModelArrayAnyOf.java
index 512a1acf067a..81d116038d0c 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfModelArrayAnyOf.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfModelArrayAnyOf.java
@@ -235,10 +235,7 @@ public class AllOfModelArrayAnyOf {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfModelArrayAnyOfAllOfAttributes.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfModelArrayAnyOfAllOfAttributes.java
index 46c3e2f03527..355585bd2a86 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfModelArrayAnyOfAllOfAttributes.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfModelArrayAnyOfAllOfAttributes.java
@@ -156,10 +156,7 @@ public class AllOfModelArrayAnyOfAllOfAttributes {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfModelArrayAnyOfAllOfLinkListColumn1.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfModelArrayAnyOfAllOfLinkListColumn1.java
index d2acc50a85f5..526cfce300fe 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfModelArrayAnyOfAllOfLinkListColumn1.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfModelArrayAnyOfAllOfLinkListColumn1.java
@@ -166,10 +166,7 @@ public class AllOfModelArrayAnyOfAllOfLinkListColumn1 {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
index 13a62a37a16e..3a422b8c2d07 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
@@ -155,10 +155,7 @@ public class AllOfRefToDouble {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
index 26d860e20b8d..841dfa0ed7da 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
@@ -155,10 +155,7 @@ public class AllOfRefToFloat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfRefToLong.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
index 41ac7b138f98..afd644b1f73d 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
@@ -155,10 +155,7 @@ public class AllOfRefToLong {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Animal.java
index e38a750ec774..a5dd970c88a9 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Animal.java
@@ -182,10 +182,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Apple.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Apple.java
index 794586ef5c0f..a07e2c9cf5f8 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Apple.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Apple.java
@@ -181,10 +181,7 @@ public class Apple {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AppleReq.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AppleReq.java
index 5e36df519b05..56d1deb30d56 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AppleReq.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AppleReq.java
@@ -135,10 +135,7 @@ public class AppleReq {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayDefault.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayDefault.java
index 3061e86e0520..326a12d0410a 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayDefault.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayDefault.java
@@ -199,10 +199,7 @@ public class ArrayDefault {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 09d6ee5603a1..134763f14205 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -166,10 +166,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfInlineAllOf.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfInlineAllOf.java
index 6bbfb211f8cf..cd3b42f8a91f 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfInlineAllOf.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfInlineAllOf.java
@@ -218,10 +218,7 @@ public class ArrayOfInlineAllOf {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfInlineAllOfArrayAllofDogPropertyInner.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfInlineAllOfArrayAllofDogPropertyInner.java
index 34a505f3ca6e..1342628771f5 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfInlineAllOfArrayAllofDogPropertyInner.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfInlineAllOfArrayAllofDogPropertyInner.java
@@ -181,10 +181,7 @@ public class ArrayOfInlineAllOfArrayAllofDogPropertyInner {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 47fb4c0dd1ec..88f8d40c92c0 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -166,10 +166,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayTest.java
index 009cc5a7c738..45bd9e75c87a 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -234,10 +234,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Banana.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Banana.java
index 97dd43f76fdc..58f088833f63 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Banana.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Banana.java
@@ -156,10 +156,7 @@ public class Banana {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/BananaReq.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/BananaReq.java
index da38f29b3ec0..7ac124a95c7e 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/BananaReq.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/BananaReq.java
@@ -136,10 +136,7 @@ public class BananaReq {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/BasquePig.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/BasquePig.java
index 879e4b59c0d7..a031b5d51d1d 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/BasquePig.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/BasquePig.java
@@ -155,10 +155,7 @@ public class BasquePig {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Capitalization.java
index 139890755296..51cd3f35bd15 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -285,10 +285,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Cat.java
index 0d4ae32f5a12..9932566883db 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Cat.java
@@ -160,10 +160,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Category.java
index fb129a1c64c0..a6385e4494f7 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Category.java
@@ -181,10 +181,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ClassModel.java
index cc9d15e39d74..b5bbc18c2369 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -155,10 +155,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Client.java
index 5bcd45d54255..b86c9775b388 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Client.java
@@ -155,10 +155,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
index 5db5ca7dd714..9dcaec3aa556 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
@@ -181,10 +181,7 @@ public class ComplexQuadrilateral {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/DanishPig.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/DanishPig.java
index 73189ea29c72..fd25a3701261 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/DanishPig.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/DanishPig.java
@@ -155,10 +155,7 @@ public class DanishPig {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index ddb349efb955..2e247a608841 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -157,10 +157,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Dog.java
index 0a84c2449b05..66456e5b89d6 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Dog.java
@@ -159,10 +159,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Drawing.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Drawing.java
index 03352cf0189f..b1ba3ee10f08 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Drawing.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Drawing.java
@@ -259,10 +259,7 @@ public class Drawing {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumArrays.java
index a5867e20a266..68700fc7c957 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -295,10 +295,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumStringDiscriminator.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumStringDiscriminator.java
index 304162fbc197..e2cd88424b4d 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumStringDiscriminator.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumStringDiscriminator.java
@@ -208,10 +208,7 @@ public class EnumStringDiscriminator {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumTest.java
index 14b4090d7792..df9e2d19e365 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -648,10 +648,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EquilateralTriangle.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
index a83c2164577b..bb308e32c7a4 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
@@ -181,10 +181,7 @@ public class EquilateralTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 560623f2ee13..d804b372a919 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -192,10 +192,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Foo.java
index c72212e5ed85..3a17bc5d07fb 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Foo.java
@@ -155,10 +155,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index 576297e8c1fa..998d0c56db41 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -156,10 +156,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FormatTest.java
index 09baf201e9ac..045fea669684 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -586,10 +586,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FreeFormObjectTestClass.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FreeFormObjectTestClass.java
index 5d5c61e85b46..535a852bf830 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FreeFormObjectTestClass.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FreeFormObjectTestClass.java
@@ -182,10 +182,7 @@ public class FreeFormObjectTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/GrandparentAnimal.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
index 5d0d540a54bf..cf4ac73d9944 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
@@ -156,10 +156,7 @@ public class GrandparentAnimal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 16f511ea792a..8a9ee06d9abf 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -174,10 +174,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index a5ad00bb709f..867e6661ce9f 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -167,10 +167,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
index eae0b737d2ac..1fdf96995c29 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
@@ -135,10 +135,7 @@ public class IsoscelesTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/MapTest.java
index a49fc3acf76c..acfb6e2f9015 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/MapTest.java
@@ -319,10 +319,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 28dea4ffc108..d89a3911f715 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -220,10 +220,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Model200Response.java
index 582494918605..fb9a67bcba8a 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -181,10 +181,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index a0686977c394..b3255bf858e2 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -207,10 +207,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelFile.java
index 08af2addd103..1a06273032b0 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -155,10 +155,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelList.java
index c15c642cabca..febc545b12a4 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelList.java
@@ -155,10 +155,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelReturn.java
index 646cc383d190..357de6d01dd8 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -155,10 +155,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelWithOneOfAnyOfProperties.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelWithOneOfAnyOfProperties.java
index 9fe5733dc6ca..94731901c7d8 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelWithOneOfAnyOfProperties.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelWithOneOfAnyOfProperties.java
@@ -183,10 +183,7 @@ public class ModelWithOneOfAnyOfProperties {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Name.java
index 6db9fbd9da98..398217717de4 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Name.java
@@ -226,10 +226,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NestedArrayWithDefaultValues.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NestedArrayWithDefaultValues.java
index 838f960b8704..c27ebc4bbeb0 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NestedArrayWithDefaultValues.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NestedArrayWithDefaultValues.java
@@ -165,10 +165,7 @@ public class NestedArrayWithDefaultValues {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPet.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPet.java
index e9f4cf85fe5b..badfd041eb29 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPet.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPet.java
@@ -437,10 +437,7 @@ public class NewPet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPetCategoryInlineAllof.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPetCategoryInlineAllof.java
index d4fb185e72f4..ea0d6fdefc35 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPetCategoryInlineAllof.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPetCategoryInlineAllof.java
@@ -208,10 +208,7 @@ public class NewPetCategoryInlineAllof {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPetCategoryInlineAllofAllOfCategoryTag.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPetCategoryInlineAllofAllOfCategoryTag.java
index 0fe4b67a8ab2..442f68c60e1d 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPetCategoryInlineAllofAllOfCategoryTag.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPetCategoryInlineAllofAllOfCategoryTag.java
@@ -181,10 +181,7 @@ public class NewPetCategoryInlineAllofAllOfCategoryTag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NullableClass.java
index 7bd0494ca528..f0837ae19e1c 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -508,10 +508,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NumberOnly.java
index 2193e5efadbf..974ce128fd36 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -156,10 +156,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 2660097c2d0b..fd3685a5e65d 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -260,10 +260,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Order.java
index 52d8775a4224..620fdfd118f0 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Order.java
@@ -340,10 +340,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/OuterComposite.java
index 69207761d866..090259d73b7b 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -208,10 +208,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ParentPet.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ParentPet.java
index 2ce5da7d4b66..19fb40e83de2 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ParentPet.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ParentPet.java
@@ -131,10 +131,7 @@ public class ParentPet extends GrandparentAnimal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java
index aee27d7bbc67..e0302016403d 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java
@@ -359,10 +359,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetComposition.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetComposition.java
index 6d9af2be83b8..d6bfdb771136 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetComposition.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetComposition.java
@@ -359,10 +359,7 @@ public class PetComposition {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetRef.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetRef.java
index c59f44b3ffcc..8c51e5228910 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetRef.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetRef.java
@@ -359,10 +359,7 @@ public class PetRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetUsingAllOf.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetUsingAllOf.java
index 73c812dd5cee..3feb7bab9bb2 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetUsingAllOf.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetUsingAllOf.java
@@ -359,10 +359,7 @@ public class PetUsingAllOf {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetWithRequiredTags.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetWithRequiredTags.java
index 86c176d1954c..a74b291ad99a 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetWithRequiredTags.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetWithRequiredTags.java
@@ -359,10 +359,7 @@ public class PetWithRequiredTags {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PropertyNameCollision.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PropertyNameCollision.java
index 42dde9baf4f0..6b553a2c1cce 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PropertyNameCollision.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PropertyNameCollision.java
@@ -207,10 +207,7 @@ public class PropertyNameCollision {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
index 0f444edba57c..e20e8b23276f 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
@@ -155,10 +155,7 @@ public class QuadrilateralInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index ad7d1a69064b..696892ba478e 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -180,10 +180,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/RequiredNullableBody.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/RequiredNullableBody.java
index 10662b8e1020..a89e16156e81 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/RequiredNullableBody.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/RequiredNullableBody.java
@@ -599,10 +599,7 @@ public class RequiredNullableBody {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ScaleneTriangle.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
index d97d278c11d9..9abf449b830c 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
@@ -181,10 +181,7 @@ public class ScaleneTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ShapeInterface.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ShapeInterface.java
index c27f9b9f69e6..e8620348e6df 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ShapeInterface.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ShapeInterface.java
@@ -155,10 +155,7 @@ public class ShapeInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
index 5c95b5e7dd0b..a9aca0a1c606 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
@@ -181,10 +181,7 @@ public class SimpleQuadrilateral {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/SpecialModelName.java
index 0b3470323666..52e8b84b1371 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -181,10 +181,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Tag.java
index 0d593ca78284..c5847caef86f 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Tag.java
@@ -181,10 +181,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 7073939e13cb..755bfc7dfd06 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -155,10 +155,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/TriangleInterface.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/TriangleInterface.java
index 2dc37b579f2e..46facd349f1b 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/TriangleInterface.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/TriangleInterface.java
@@ -155,10 +155,7 @@ public class TriangleInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/User.java
index 4dc9947db645..8d547123a620 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/User.java
@@ -453,10 +453,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Variable.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Variable.java
index 6f3fece8231a..b9fde34d8928 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Variable.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Variable.java
@@ -182,10 +182,7 @@ public class Variable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Whale.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Whale.java
index 37170c53813f..d46769a1b60a 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Whale.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Whale.java
@@ -207,10 +207,7 @@ public class Whale {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Zebra.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Zebra.java
index d7f96f9d314c..b6347d0ce99e 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Zebra.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Zebra.java
@@ -235,10 +235,7 @@ public class Zebra {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
index 7033e82a4998..003da2862fc0 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
@@ -140,10 +140,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
index 0469c6e4a781..9b1a3630cf44 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
@@ -141,10 +141,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
index e24a1c2f23d5..7b5a8b68df9f 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
@@ -140,10 +140,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index b40ce24969ea..e5cdeb346061 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -502,10 +502,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
index 5ac0b39014dc..d1a3ce65a270 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
@@ -140,10 +140,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
index 98827a0ae88f..0802d1c39eee 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
@@ -141,10 +141,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
index 6ff47a0a0812..800c11a22603 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
@@ -140,10 +140,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
index 973915aaac70..aac2e0e57d6c 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
@@ -140,10 +140,7 @@ public class AdditionalPropertiesString extends HashMap<String, String> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Animal.java
index 1a05ff138e8e..d55fd6c02b6e 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Animal.java
@@ -147,10 +147,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index ee5f0f6680ac..0fc9d5861ff4 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -112,10 +112,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 62a1be38bb16..cd76397c0f07 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -112,10 +112,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayTest.java
index e4d110ce49b7..ac00e128f6f7 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -195,10 +195,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/BigCat.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/BigCat.java
index ac8dc86a1372..a01fddd74ae7 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/BigCat.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/BigCat.java
@@ -163,10 +163,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Capitalization.java
index 99441b29f633..c63b4d80dc9a 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -264,10 +264,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Cat.java
index d725f6688b40..b88a4a11f482 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Cat.java
@@ -127,10 +127,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Category.java
index 165a86ba7651..91ab9f64d0ff 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Category.java
@@ -133,10 +133,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ClassModel.java
index b258b4889cdc..0d13cd88f9d2 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -99,10 +99,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Client.java
index 313d28dc2d82..8ad6ad4bc268 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Client.java
@@ -99,10 +99,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Dog.java
index 3446fb9cc5d1..9ff84ba9aa2b 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Dog.java
@@ -124,10 +124,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/EnumArrays.java
index f52a96238cd2..a6e78465aa20 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -213,10 +213,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/EnumTest.java
index 0e9c9f1caaad..eabb460a1b49 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -379,10 +379,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 53fd69d128cd..d81956e22e47 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -146,10 +146,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/FormatTest.java
index 89c548e3c8a0..62dd5e3c0746 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -554,10 +554,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 01afbfe32382..29931fb10ef8 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -123,10 +123,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/MapTest.java
index c10ad45ff6ad..e1bb743b3df5 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/MapTest.java
@@ -268,10 +268,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 133d632f8697..f8c933ae0163 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -181,10 +181,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Model200Response.java
index 2fec8df0d222..fc9976354aa9 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -133,10 +133,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index a6d5ab15ff1c..2d9b18900f1a 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -166,10 +166,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ModelFile.java
index f632352c1fb9..d06d9f3668fa 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -100,10 +100,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ModelList.java
index 08bdc3368278..9bd727fa0df4 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ModelList.java
@@ -100,10 +100,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ModelReturn.java
index 2856ab0f2eed..9d3cfebc9bb0 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -100,10 +100,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Name.java
index 0ad5d9f352c2..13208e2c3ef7 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Name.java
@@ -189,10 +189,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/NumberOnly.java
index 444c15f4e03c..d020759fd051 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -101,10 +101,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Order.java
index ee4bbc27c6c3..b00f25fddaa9 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Order.java
@@ -303,10 +303,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/OuterComposite.java
index 5532051045fd..b0b66c37afc3 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -167,10 +167,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Pet.java
index adf2a04b5331..c95d2e7cd22d 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Pet.java
@@ -330,10 +330,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 276df070fbe1..9eef77cf8025 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -131,10 +131,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/SpecialModelName.java
index dd493ae79a11..e93aa6e36f87 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -100,10 +100,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Tag.java
index 88ca39231c32..ca548546829f 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Tag.java
@@ -132,10 +132,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/TypeHolderDefault.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
index c55c6e55de95..0da2f50adeda 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
@@ -249,10 +249,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/TypeHolderExample.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/TypeHolderExample.java
index c96b64ca4748..deade3da4383 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/TypeHolderExample.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/TypeHolderExample.java
@@ -283,10 +283,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/User.java
index 53fc96ad0e54..c51fae44df3f 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/User.java
@@ -330,10 +330,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/XmlItem.java
index 73f4d779dd10..11f07c5763cd 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -1104,10 +1104,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
index e3d0d34035a8..8786c20263ac 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
@@ -97,10 +97,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
index 7f7b3b1466b4..778bb1e53ea2 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
@@ -98,10 +98,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
index 6960090991c7..67679469bd03 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
@@ -97,10 +97,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 3001ce1df574..19715716bb39 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -455,10 +455,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
index 7b284e244db4..bbf4aa8c23a3 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
@@ -97,10 +97,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
index a584a99f19ab..dd11a43008f0 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
@@ -98,10 +98,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
index ef69ca3f18ef..24b59c0e595d 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
@@ -97,10 +97,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
index 3989baf8e1dd..2c816bba1881 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
@@ -97,10 +97,7 @@ public class AdditionalPropertiesString extends HashMap<String, String> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Animal.java
index 7a27954116a0..f2caca8bbeed 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Animal.java
@@ -122,10 +122,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 0c972db73525..af1eb51cedaa 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -105,10 +105,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 91e78a43a86a..e920582981f3 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -105,10 +105,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayTest.java
index e04cc26b15d7..89eb03771fcf 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -180,10 +180,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/BigCat.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/BigCat.java
index d6d40a976b9a..9764b3a46a5b 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/BigCat.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/BigCat.java
@@ -159,10 +159,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Capitalization.java
index 9d78b47894c4..072b34c1637e 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -237,10 +237,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Cat.java
index f1e9706d372e..fbf922185151 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Cat.java
@@ -108,10 +108,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Category.java
index 9e4629292252..49f972b88ed2 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Category.java
@@ -122,10 +122,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ClassModel.java
index 5cec2831c471..290d14039c3c 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -92,10 +92,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Client.java
index eafaf9f9f80f..9fa3ac0394e1 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Client.java
@@ -92,10 +92,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Dog.java
index 8e4168f3f381..aa3398bd5934 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Dog.java
@@ -108,10 +108,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumArrays.java
index f7a7e38bc3de..3cffdd2c9acf 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -226,10 +226,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumTest.java
index 2f7eb473c48b..58cd93a25781 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -403,10 +403,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 9dd1ef645312..13ef77633239 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -135,10 +135,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FormatTest.java
index 76a5eb3547e2..b8addc8576cf 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -494,10 +494,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index d47b5d4c7e7e..f737afb21222 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -115,10 +115,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/MapTest.java
index 38f5955386cb..0fa7991a5029 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/MapTest.java
@@ -261,10 +261,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 3593e74232f3..5469432c9333 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -166,10 +166,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Model200Response.java
index eadcb162c5ef..80664ea464ee 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -121,10 +121,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index aacd836df02c..23bb849368aa 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -150,10 +150,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelFile.java
index 9484d2cde3f4..d8ca32816784 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -92,10 +92,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelList.java
index a897000c3e98..0b8371cdd880 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelList.java
@@ -92,10 +92,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelReturn.java
index a22fb32b9ec8..fb3ca5403bc9 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -92,10 +92,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Name.java
index 0422340f069f..522d13596ff9 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Name.java
@@ -174,10 +174,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/NumberOnly.java
index bb838613b55a..dc7f971026a4 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -94,10 +94,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Order.java
index 19da9b4cee1b..1bd4fe6ddfff 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Order.java
@@ -288,10 +288,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/OuterComposite.java
index 25734b509c70..00355ac0e015 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -152,10 +152,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Pet.java
index 1ed5d7515c0e..737fff200aae 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Pet.java
@@ -313,10 +313,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 5211756d615d..bfeceb5b0000 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -122,10 +122,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/SpecialModelName.java
index bfb7e8647cd7..6cca908913d9 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -92,10 +92,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Tag.java
index b5f369a58cfd..37bea864c27f 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Tag.java
@@ -121,10 +121,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/TypeHolderDefault.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
index f29daad4e854..08e816144111 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
@@ -226,10 +226,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/TypeHolderExample.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/TypeHolderExample.java
index 0fe89f06337e..0f3a961113fd 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/TypeHolderExample.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/TypeHolderExample.java
@@ -256,10 +256,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/User.java
index e991ea19e786..2b6ec35c201f 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/User.java
@@ -295,10 +295,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/XmlItem.java
index f473b8f96795..8b0af0ca277e 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -985,10 +985,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-nullable-arrays/src/main/java/org/openapitools/client/model/ByteArrayObject.java b/samples/client/petstore/java/restclient-nullable-arrays/src/main/java/org/openapitools/client/model/ByteArrayObject.java
index 9330c50574ff..511a39d14550 100644
--- a/samples/client/petstore/java/restclient-nullable-arrays/src/main/java/org/openapitools/client/model/ByteArrayObject.java
+++ b/samples/client/petstore/java/restclient-nullable-arrays/src/main/java/org/openapitools/client/model/ByteArrayObject.java
@@ -256,10 +256,7 @@ public class ByteArrayObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/restclient-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Category.java
index f41657f87ed7..d0136291aa6c 100644
--- a/samples/client/petstore/java/restclient-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/restclient-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Category.java
@@ -128,10 +128,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/restclient-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Pet.java
index 50f20718d4b3..6c7cf0c4f3ac 100644
--- a/samples/client/petstore/java/restclient-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/restclient-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Pet.java
@@ -316,10 +316,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/restclient-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Tag.java
index a4c750c9ca78..20670e2a9aa3 100644
--- a/samples/client/petstore/java/restclient-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/restclient-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Tag.java
@@ -128,10 +128,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/restclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Category.java
index c896cf909c0d..1af178d2b9b6 100644
--- a/samples/client/petstore/java/restclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/restclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Category.java
@@ -127,10 +127,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/restclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Pet.java
index 76cb8df61cec..393d24554dee 100644
--- a/samples/client/petstore/java/restclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/restclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Pet.java
@@ -315,10 +315,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/restclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Tag.java
index 3fdb59ec3c00..442ede1c2aed 100644
--- a/samples/client/petstore/java/restclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/restclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Tag.java
@@ -127,10 +127,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 94e0895532f1..17caf2df45c6 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -149,10 +149,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 8857b55d2d90..3d57d7f82f7b 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -132,10 +132,7 @@ public class AllOfWithSingleRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Animal.java
index e43b78062751..3c07a20ca7f3 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Animal.java
@@ -144,10 +144,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index aa48153b53f6..0d7dc81b7333 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -110,10 +110,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index af2ac06a014b..31b27b9ea24a 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -110,10 +110,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ArrayTest.java
index e15b2aaf21e4..e3112ece9f7d 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -192,10 +192,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Capitalization.java
index f7a11268af87..7fd2ef5262c3 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -263,10 +263,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Cat.java
index c73e5828ed3a..5211a0dbd0d0 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Cat.java
@@ -123,10 +123,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Category.java
index 256e93768cb4..df07b743e627 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Category.java
@@ -131,10 +131,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 55be5abfe8a3..a9c768ad301f 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -135,10 +135,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ClassModel.java
index 7c671046aa8e..be618e176ede 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -99,10 +99,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Client.java
index dc6c87cf1171..0880c3868a69 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Client.java
@@ -98,10 +98,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 8772020da439..1b9352098209 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -100,10 +100,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Dog.java
index 571a8f0e9584..e4504462b164 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Dog.java
@@ -123,10 +123,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/EnumArrays.java
index 1d965b8e79d3..4a75af360ce7 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -212,10 +212,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/EnumTest.java
index 834dc0c0e962..48ac5d68ee6a 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -501,10 +501,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index a7af3cd4419e..44f0e80cf623 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -143,10 +143,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index d054a2b84b30..bfbeb33b94cb 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -143,10 +143,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Foo.java
index 599f593a69e7..27b1b9fdf13f 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Foo.java
@@ -98,10 +98,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index c2d9dcda3469..1483b4f1ae4b 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -100,10 +100,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/FormatTest.java
index c78a4fd2ee7a..26fbc60087a8 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -609,10 +609,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 91388db85edb..ffafc0ced08b 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -122,10 +122,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 5bba4f7a1eb3..cce85065800f 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -122,10 +122,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/MapTest.java
index 26c207c4b0be..cefae94e317b 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/MapTest.java
@@ -266,10 +266,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index e60ed74b9d27..9c11e2b51f9b 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -177,10 +177,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Model200Response.java
index 2f0d1738fdcb..bfd45bd9c2ea 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -133,10 +133,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index fe61b77bce22..146ecf7e7921 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -165,10 +165,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ModelFile.java
index 8f62d8e1d488..ad614718b04f 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -100,10 +100,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ModelList.java
index 5f98c9a8ef98..a22874152ebb 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ModelList.java
@@ -99,10 +99,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ModelReturn.java
index 81df0e25db22..d226cf11a66e 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -100,10 +100,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Name.java
index 43bfb6398c71..1f318526029f 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Name.java
@@ -188,10 +188,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/NullableClass.java
index c04182737a68..6cb1b7262ccf 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -677,10 +677,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/NumberOnly.java
index e305f75c3d79..3857b4e060f7 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -99,10 +99,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index c634fbb95ed3..f0aa458bcbe8 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -216,10 +216,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Order.java
index 0571394f1d29..6710d845c3f8 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Order.java
@@ -301,10 +301,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/OuterComposite.java
index 884bff244332..5d9a42f858e6 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -165,10 +165,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 5883c7b49849..8f2cc9a292f4 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -99,10 +99,7 @@ public class OuterObjectWithEnumProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index b364f7018662..7cec4d9bf9d8 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -199,10 +199,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Pet.java
index 98d71d7f8abd..cf47d153a724 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Pet.java
@@ -325,10 +325,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 17ec494e6378..54f61802208b 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -130,10 +130,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/SpecialModelName.java
index 3bc08073d55d..3cff43f13f90 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -99,10 +99,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Tag.java
index db296ab6aa6f..90e6d77efde4 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/Tag.java
@@ -131,10 +131,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index cbea25b3f578..88fb857cd7a4 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -148,10 +148,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/User.java
index e587b0d81f39..e95a8fd6e3db 100644
--- a/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/restclient-swagger2/src/main/java/org/openapitools/client/model/User.java
@@ -329,10 +329,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 8313dbb92766..5209ab0528fe 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -146,10 +146,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index b724ff955d75..c495b10ba37c 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -129,10 +129,7 @@ public class AllOfWithSingleRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Animal.java
index 133d3296a735..0e00d54b29d2 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Animal.java
@@ -141,10 +141,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index c1686b3ae895..7950b4751c3d 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -108,10 +108,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 044c05679840..e7cefc448dce 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -108,10 +108,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ArrayTest.java
index 9e50c381b993..7b7aaf2d8392 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -188,10 +188,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Capitalization.java
index 17347fa1efb2..578613fc5d9f 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -256,10 +256,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Cat.java
index 62b8310a2f15..95800cb15169 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Cat.java
@@ -121,10 +121,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Category.java
index 640e09d1d864..c32f131457d4 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Category.java
@@ -128,10 +128,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 6b1557367fe0..124cda618b34 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -133,10 +133,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ClassModel.java
index 03dd0e56fe88..4cf87ce92d21 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -96,10 +96,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Client.java
index 9a3a2f04512d..78411666b723 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Client.java
@@ -96,10 +96,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index cd096fc4ec58..4938ba7c36a5 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -98,10 +98,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Dog.java
index dc0486830516..68e6bf19e54b 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Dog.java
@@ -121,10 +121,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/EnumArrays.java
index b79269092b6b..66e4391dfbbb 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -209,10 +209,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/EnumTest.java
index 102e04c78305..8d361c6e0d59 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -492,10 +492,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index 96a349de54ea..4f78b6d415b3 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -140,10 +140,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 04df17f59079..2cfa12acce34 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -140,10 +140,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Foo.java
index e07f877a8309..8da1ec3cbc81 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Foo.java
@@ -96,10 +96,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index 01685214d6d8..6f06d417e4aa 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -98,10 +98,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/FormatTest.java
index a4ff19bcaae2..4dc44ad532a8 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -592,10 +592,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 40dd98e9af38..eeed9e75d510 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -119,10 +119,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 47b37cad2f1c..b8ef4db38bde 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -119,10 +119,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/MapTest.java
index 44ce9c265cee..3790ccb28ab8 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/MapTest.java
@@ -261,10 +261,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 96cbaab4461b..e7f3ac2f49de 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -173,10 +173,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Model200Response.java
index 99e84ddb7374..95ec266d34c4 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -129,10 +129,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index d35943178e57..963cd2a29632 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -161,10 +161,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ModelFile.java
index 0436e3f80124..1c129bd05fc1 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -97,10 +97,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ModelList.java
index 6fc065284c5d..b3640df8bde4 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ModelList.java
@@ -97,10 +97,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ModelReturn.java
index b70ee2cb55ef..11a137a2cc84 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -97,10 +97,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Name.java
index 9c5eece550eb..15ace26422c4 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Name.java
@@ -182,10 +182,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/NullableClass.java
index 47f86498a586..c3a54b3cbe07 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -664,10 +664,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/NumberOnly.java
index b0ca116680f9..9e906fb449d7 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -97,10 +97,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 3df0f6f53f5a..e5362b358b05 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -211,10 +211,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Order.java
index 816bbb108f84..dfd8675ef792 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Order.java
@@ -294,10 +294,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/OuterComposite.java
index 31d4c273541a..99513dff35c4 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -161,10 +161,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 9e4998d5484f..5c5cdb93e322 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -97,10 +97,7 @@ public class OuterObjectWithEnumProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index b7c6557d5c37..f921780e574e 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -196,10 +196,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Pet.java
index ed16a9df9034..5715bef8acf4 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Pet.java
@@ -318,10 +318,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 72ef1335d74c..829a59e38ec9 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -127,10 +127,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/SpecialModelName.java
index e78400e8a27f..9505332deda7 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -97,10 +97,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Tag.java
index ce45441ee03f..6284bd4382b8 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/Tag.java
@@ -128,10 +128,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index e66505b3463a..2f6aa966ef08 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -146,10 +146,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/User.java
index 458444105335..75ed3841cf72 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter-static/src/main/java/org/openapitools/client/model/User.java
@@ -320,10 +320,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 8313dbb92766..5209ab0528fe 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -146,10 +146,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index b724ff955d75..c495b10ba37c 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -129,10 +129,7 @@ public class AllOfWithSingleRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Animal.java
index 133d3296a735..0e00d54b29d2 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Animal.java
@@ -141,10 +141,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index c1686b3ae895..7950b4751c3d 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -108,10 +108,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 044c05679840..e7cefc448dce 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -108,10 +108,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayTest.java
index 9e50c381b993..7b7aaf2d8392 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -188,10 +188,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Capitalization.java
index 17347fa1efb2..578613fc5d9f 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -256,10 +256,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Cat.java
index 62b8310a2f15..95800cb15169 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Cat.java
@@ -121,10 +121,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Category.java
index 640e09d1d864..c32f131457d4 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Category.java
@@ -128,10 +128,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 6b1557367fe0..124cda618b34 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -133,10 +133,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ClassModel.java
index 03dd0e56fe88..4cf87ce92d21 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -96,10 +96,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Client.java
index 9a3a2f04512d..78411666b723 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Client.java
@@ -96,10 +96,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index cd096fc4ec58..4938ba7c36a5 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -98,10 +98,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Dog.java
index dc0486830516..68e6bf19e54b 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Dog.java
@@ -121,10 +121,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/EnumArrays.java
index b79269092b6b..66e4391dfbbb 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -209,10 +209,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/EnumTest.java
index 102e04c78305..8d361c6e0d59 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -492,10 +492,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index 96a349de54ea..4f78b6d415b3 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -140,10 +140,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 04df17f59079..2cfa12acce34 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -140,10 +140,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Foo.java
index e07f877a8309..8da1ec3cbc81 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Foo.java
@@ -96,10 +96,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index 01685214d6d8..6f06d417e4aa 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -98,10 +98,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FormatTest.java
index a4ff19bcaae2..4dc44ad532a8 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -592,10 +592,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 40dd98e9af38..eeed9e75d510 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -119,10 +119,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 47b37cad2f1c..b8ef4db38bde 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -119,10 +119,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/MapTest.java
index 44ce9c265cee..3790ccb28ab8 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/MapTest.java
@@ -261,10 +261,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 96cbaab4461b..e7f3ac2f49de 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -173,10 +173,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Model200Response.java
index 99e84ddb7374..95ec266d34c4 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -129,10 +129,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index d35943178e57..963cd2a29632 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -161,10 +161,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelFile.java
index 0436e3f80124..1c129bd05fc1 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -97,10 +97,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelList.java
index 6fc065284c5d..b3640df8bde4 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelList.java
@@ -97,10 +97,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelReturn.java
index b70ee2cb55ef..11a137a2cc84 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -97,10 +97,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Name.java
index 9c5eece550eb..15ace26422c4 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Name.java
@@ -182,10 +182,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/NullableClass.java
index 47f86498a586..c3a54b3cbe07 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -664,10 +664,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/NumberOnly.java
index b0ca116680f9..9e906fb449d7 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -97,10 +97,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 3df0f6f53f5a..e5362b358b05 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -211,10 +211,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Order.java
index 816bbb108f84..dfd8675ef792 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Order.java
@@ -294,10 +294,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/OuterComposite.java
index 31d4c273541a..99513dff35c4 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -161,10 +161,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 9e4998d5484f..5c5cdb93e322 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -97,10 +97,7 @@ public class OuterObjectWithEnumProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index b7c6557d5c37..f921780e574e 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -196,10 +196,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Pet.java
index ed16a9df9034..5715bef8acf4 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Pet.java
@@ -318,10 +318,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 72ef1335d74c..829a59e38ec9 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -127,10 +127,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/SpecialModelName.java
index e78400e8a27f..9505332deda7 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -97,10 +97,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Tag.java
index ce45441ee03f..6284bd4382b8 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Tag.java
@@ -128,10 +128,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index e66505b3463a..2f6aa966ef08 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -146,10 +146,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/User.java
index 458444105335..75ed3841cf72 100644
--- a/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/restclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/User.java
@@ -320,10 +320,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index f8aec1faa30d..3f472fbb6262 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -146,10 +146,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index b724ff955d75..c495b10ba37c 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -129,10 +129,7 @@ public class AllOfWithSingleRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Animal.java
index 133d3296a735..0e00d54b29d2 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Animal.java
@@ -141,10 +141,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 60caaaa4a006..eeea1a5879d6 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -108,10 +108,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index e4ad03ab4d53..e3b250497011 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -108,10 +108,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ArrayTest.java
index 264ce831c5cc..0fa5b01171b6 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -188,10 +188,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Capitalization.java
index 17347fa1efb2..578613fc5d9f 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -256,10 +256,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Cat.java
index 62b8310a2f15..95800cb15169 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Cat.java
@@ -121,10 +121,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Category.java
index 640e09d1d864..c32f131457d4 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Category.java
@@ -128,10 +128,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 6b1557367fe0..124cda618b34 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -133,10 +133,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ClassModel.java
index 03dd0e56fe88..4cf87ce92d21 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -96,10 +96,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Client.java
index 9a3a2f04512d..78411666b723 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Client.java
@@ -96,10 +96,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index cd096fc4ec58..4938ba7c36a5 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -98,10 +98,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Dog.java
index dc0486830516..68e6bf19e54b 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Dog.java
@@ -121,10 +121,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/EnumArrays.java
index e5b4c16737e7..d3a77e720789 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -209,10 +209,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/EnumTest.java
index 102e04c78305..8d361c6e0d59 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -492,10 +492,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index 998006b3ee91..28bedbdeceab 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -140,10 +140,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 0018d667bbde..25ad1a8ffcca 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -140,10 +140,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Foo.java
index e07f877a8309..8da1ec3cbc81 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Foo.java
@@ -96,10 +96,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index 01685214d6d8..6f06d417e4aa 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -98,10 +98,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/FormatTest.java
index a4ff19bcaae2..4dc44ad532a8 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -592,10 +592,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 40dd98e9af38..eeed9e75d510 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -119,10 +119,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 47b37cad2f1c..b8ef4db38bde 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -119,10 +119,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/MapTest.java
index 028035e2a8e2..5861b310ecf1 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/MapTest.java
@@ -261,10 +261,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index f091b416ae85..4b8faee265e4 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -173,10 +173,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Model200Response.java
index 99e84ddb7374..95ec266d34c4 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -129,10 +129,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index d35943178e57..963cd2a29632 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -161,10 +161,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ModelFile.java
index 0436e3f80124..1c129bd05fc1 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -97,10 +97,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ModelList.java
index 6fc065284c5d..b3640df8bde4 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ModelList.java
@@ -97,10 +97,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ModelReturn.java
index b70ee2cb55ef..11a137a2cc84 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -97,10 +97,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Name.java
index 9c5eece550eb..15ace26422c4 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Name.java
@@ -182,10 +182,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/NullableClass.java
index ca50bb6dd235..19af5455acdd 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -664,10 +664,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/NumberOnly.java
index b0ca116680f9..9e906fb449d7 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -97,10 +97,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index a2e6dfcdbe6c..07c1e0996293 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -211,10 +211,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Order.java
index 816bbb108f84..dfd8675ef792 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Order.java
@@ -294,10 +294,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/OuterComposite.java
index 31d4c273541a..99513dff35c4 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -161,10 +161,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 9e4998d5484f..5c5cdb93e322 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -97,10 +97,7 @@ public class OuterObjectWithEnumProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index b7c6557d5c37..f921780e574e 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -196,10 +196,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Pet.java
index a20a6856e698..211a34fc9bab 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Pet.java
@@ -318,10 +318,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 72ef1335d74c..829a59e38ec9 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -127,10 +127,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/SpecialModelName.java
index e78400e8a27f..9505332deda7 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -97,10 +97,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Tag.java
index ce45441ee03f..6284bd4382b8 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/Tag.java
@@ -128,10 +128,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index e66505b3463a..2f6aa966ef08 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -146,10 +146,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/User.java
index 458444105335..75ed3841cf72 100644
--- a/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/restclient/src/main/java/org/openapitools/client/model/User.java
@@ -320,10 +320,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index ca22cd6e8c92..1c400a0636c9 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -145,10 +145,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 6fc838649a61..ff6881338a4b 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -128,10 +128,7 @@ public class AllOfWithSingleRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Animal.java
index 0b680e4a8098..112c0fb4e844 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Animal.java
@@ -140,10 +140,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 05aae9025b11..f999a3281c91 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index a57ad8474113..f5df05c07d07 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayTest.java
index 3dfa034fec8c..0c22d54edea7 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -187,10 +187,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Capitalization.java
index b2db0dd9497c..96cb38ffbd3a 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -255,10 +255,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Cat.java
index d71faa40c12d..692f5d965f3d 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Cat.java
@@ -120,10 +120,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Category.java
index b06cb8f143e1..c56efa1b8a0b 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Category.java
@@ -127,10 +127,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 1fcd981e18c5..812336c278c3 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -132,10 +132,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ClassModel.java
index 025a660fb102..1403f962eb6b 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -95,10 +95,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Client.java
index f88005a259bb..45d082779ab1 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Client.java
@@ -95,10 +95,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 24c7e5e5ddef..a8bb6ff86252 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -97,10 +97,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Dog.java
index 3dd517f475d9..0095b95b0c7c 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Dog.java
@@ -120,10 +120,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/EnumArrays.java
index 9da3fa9a02a2..8dbd1f17a19f 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -208,10 +208,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/EnumTest.java
index a9b99f7f7221..fc198e317b46 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -491,10 +491,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index f6da99504d3c..d28440acf3b0 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -139,10 +139,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 6ed704664d75..308d71e3c0c7 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -139,10 +139,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Foo.java
index 91253b36f172..c2f49aed150f 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Foo.java
@@ -95,10 +95,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index c2b9015e9db8..ac5fce79dae8 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -97,10 +97,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FormatTest.java
index fe966603c8e2..5248ba73b78b 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -591,10 +591,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 0a02e6ac5bd2..3abffcdb884c 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -118,10 +118,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index f9379a3b20fe..dd6054080b63 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -118,10 +118,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/MapTest.java
index 10cbd3663bf0..7fb194942948 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/MapTest.java
@@ -260,10 +260,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 148ff9614e56..faa706c19210 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -172,10 +172,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Model200Response.java
index 0662306cdfba..f555afa8b655 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -128,10 +128,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index c953c34819d3..c80bdaaf8c77 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -160,10 +160,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ModelFile.java
index 715f1a5940a4..7cabeb1588a8 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -96,10 +96,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ModelList.java
index b8b0ff69d52b..068f29bcd09c 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ModelList.java
@@ -96,10 +96,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ModelReturn.java
index 3bdefdbe181b..a7c0f9214aa5 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -96,10 +96,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Name.java
index b1fc0834268c..75523ca8acc0 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Name.java
@@ -181,10 +181,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/NullableClass.java
index 28b41e8da114..e54f4e219e6b 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -653,10 +653,7 @@ public class NullableClass extends HashMap<String, Object> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/NumberOnly.java
index 36d4f5cd0f62..de65f8c39a85 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -96,10 +96,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 63665bf5074c..0f70ada5df86 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -210,10 +210,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Order.java
index 7e5b39766e8f..642eccbc1384 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Order.java
@@ -293,10 +293,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/OuterComposite.java
index 2c9c2d8be38e..60c4a04e7dff 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -160,10 +160,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 675efcca5779..a06953c57d37 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -96,10 +96,7 @@ public class OuterObjectWithEnumProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index bd1d047e86df..8d532ba19c89 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -195,10 +195,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Pet.java
index 2fddb31d41f8..5681216244a3 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Pet.java
@@ -317,10 +317,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index b341198f23f4..a9faae1c3d41 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -126,10 +126,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/SpecialModelName.java
index aba001bad4a2..ba4d6f65b975 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -96,10 +96,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Tag.java
index 4a44520fada0..ceb3d1ed3036 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Tag.java
@@ -127,10 +127,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 45896a5b4a23..e10cb3bfd43f 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -137,10 +137,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/User.java
index 8427dda3f605..c871f7cb2a2f 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/User.java
@@ -319,10 +319,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Category.java
index 7f52e59c4911..b6aaa7445e9a 100644
--- a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Category.java
@@ -136,10 +136,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index a8f9216ad931..e3da95b5d72e 100644
--- a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -170,10 +170,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Order.java
index 95149715e1bc..109239fb0ae9 100644
--- a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Order.java
@@ -306,10 +306,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Pet.java
index 62a03348d728..1f0d88bb2f58 100644
--- a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Pet.java
@@ -328,10 +328,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Tag.java
index 150189201f3c..b9c83ff62a09 100644
--- a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Tag.java
@@ -136,10 +136,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/User.java
index d2114bb7155f..6e1af9c58fe6 100644
--- a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/User.java
@@ -334,10 +334,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/resttemplate-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Category.java
index f41657f87ed7..d0136291aa6c 100644
--- a/samples/client/petstore/java/resttemplate-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/resttemplate-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Category.java
@@ -128,10 +128,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/resttemplate-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Pet.java
index 50f20718d4b3..6c7cf0c4f3ac 100644
--- a/samples/client/petstore/java/resttemplate-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/resttemplate-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Pet.java
@@ -316,10 +316,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/resttemplate-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Tag.java
index a4c750c9ca78..20670e2a9aa3 100644
--- a/samples/client/petstore/java/resttemplate-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/resttemplate-springBoot4-jackson2/src/main/java/org/openapitools/client/model/Tag.java
@@ -128,10 +128,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/resttemplate-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Category.java
index c896cf909c0d..1af178d2b9b6 100644
--- a/samples/client/petstore/java/resttemplate-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/resttemplate-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Category.java
@@ -127,10 +127,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/resttemplate-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Pet.java
index 76cb8df61cec..393d24554dee 100644
--- a/samples/client/petstore/java/resttemplate-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/resttemplate-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Pet.java
@@ -315,10 +315,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/resttemplate-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Tag.java
index 3fdb59ec3c00..442ede1c2aed 100644
--- a/samples/client/petstore/java/resttemplate-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/resttemplate-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Tag.java
@@ -127,10 +127,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Category.java
index 708471f8f875..f0f5e58d9fa6 100644
--- a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Category.java
@@ -133,10 +133,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 598d3b302308..fb0f2db6b111 100644
--- a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -167,10 +167,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Order.java
index bb52c8c6f8a6..a0e0a1e8ae76 100644
--- a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Order.java
@@ -303,10 +303,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Pet.java
index 4350e1e0f6ec..1609944003eb 100644
--- a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Pet.java
@@ -325,10 +325,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Tag.java
index eee82ea791ab..d5dd3ca2d23f 100644
--- a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Tag.java
@@ -133,10 +133,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/User.java
index f6c4e5e27309..f322fbe63759 100644
--- a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/User.java
@@ -331,10 +331,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Category.java
index 70c09d520693..219391fcbf45 100644
--- a/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Category.java
@@ -132,10 +132,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 146902f4decc..cbad39bf261e 100644
--- a/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -166,10 +166,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Order.java
index 23e2cd0b273c..4ec2534c2171 100644
--- a/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Order.java
@@ -302,10 +302,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Pet.java
index f013611b1f6c..5d8d490dd806 100644
--- a/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Pet.java
@@ -324,10 +324,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Tag.java
index d722880f0d78..fcf5e16a45b8 100644
--- a/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Tag.java
@@ -132,10 +132,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/User.java
index 1c76a09136ec..678e8443faed 100644
--- a/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/User.java
@@ -330,10 +330,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index f7261831450b..bdc27e8bf973 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -163,10 +163,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 25e4f3aad07b..57d4f8ecf45c 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -142,10 +142,7 @@ public class AllOfWithSingleRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Animal.java
index 68f7ff530c92..9c850cb72b2e 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Animal.java
@@ -154,10 +154,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index cc80464ecb3d..f1a5b0738b1d 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -120,10 +120,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index f9d67f4895ed..809a9904ea31 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -120,10 +120,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayTest.java
index 352164ff8201..a5fae0f85bb8 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -210,10 +210,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Capitalization.java
index e089067c3e49..34d30be2f21f 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -281,10 +281,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Cat.java
index b91e6c6fa924..7613f69a7257 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Cat.java
@@ -131,10 +131,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Category.java
index 2d9b1716b641..fea85a361cbc 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Category.java
@@ -141,10 +141,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index d5e72121c79e..b66f22aaf696 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -143,10 +143,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ClassModel.java
index 49ce22461640..7e80fca96af8 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -106,10 +106,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Client.java
index 1749ed8d7ddb..9c856acd51b0 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Client.java
@@ -106,10 +106,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index d3331f768f5d..baff76d79625 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -108,10 +108,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Dog.java
index dd76cd76ece7..16ef4093f359 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Dog.java
@@ -131,10 +131,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/EnumArrays.java
index 70244070545f..99df2e466a99 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -232,10 +232,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/EnumTest.java
index 19d8f9f02c75..374b2c513109 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -540,10 +540,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index 5cede464ff31..842ec9c065ef 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -155,10 +155,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 00660821e982..ab9b0e242b68 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -155,10 +155,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Foo.java
index e331f8fc8037..933b947288d9 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Foo.java
@@ -106,10 +106,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index 44f20ce90f13..616a8297f08c 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -108,10 +108,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FormatTest.java
index 293649f79a40..aaec7d69296a 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -648,10 +648,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 2d5210298fde..abe66a152724 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -118,10 +118,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index ff1734992dbb..dce852adce32 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -128,10 +128,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/MapTest.java
index dec1a7ff9fa9..d77f3a1f4e96 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/MapTest.java
@@ -292,10 +292,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 50fae959422d..29663c2298e5 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -192,10 +192,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Model200Response.java
index 5a739c5cfb49..d760fc72dfcb 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -142,10 +142,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index a9a3335e1773..1a7d773e91a4 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -177,10 +177,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ModelFile.java
index 89c520c91ec3..f5d98c922f90 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -107,10 +107,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ModelList.java
index f29bc6f2aade..919dcb3e1a93 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ModelList.java
@@ -107,10 +107,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ModelReturn.java
index 092b2ccb1d8c..02ca0d334106 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -107,10 +107,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Name.java
index ec3580777cfc..79b71a72f9e1 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Name.java
@@ -187,10 +187,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/NullableClass.java
index 5b924d026718..400a90929531 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -706,10 +706,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/NumberOnly.java
index 15fc38869774..e0cf36437a4d 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -107,10 +107,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 8416061a4ac5..4c408956060b 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -232,10 +232,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Order.java
index 3f577056f960..d0da4c06b59e 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Order.java
@@ -325,10 +325,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/OuterComposite.java
index 938fc45bd18f..b98f0bbe2e24 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -177,10 +177,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 56a0741bde74..b6ceb8d6c83f 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -107,10 +107,7 @@ public class OuterObjectWithEnumProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index ad3ae40cfcc3..71841742318f 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -211,10 +211,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Pet.java
index bf414efa5c02..e6b2dd857b73 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Pet.java
@@ -354,10 +354,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 6c544c34a173..ba5292cac767 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -129,10 +129,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/SpecialModelName.java
index 3c7a0e4c8b7c..c2b27bc86478 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -107,10 +107,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Tag.java
index c60ba1ef3be1..14e35957d23d 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Tag.java
@@ -141,10 +141,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 5f475b518d9c..1e8fe995d8c9 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -156,10 +156,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/User.java
index 82ca31f2005a..0bd30caf8164 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/User.java
@@ -351,10 +351,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 58ac03dcba8a..86bfb514ca19 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -154,10 +154,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 0668977faee0..a6206bf43cd8 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -137,10 +137,7 @@ public class AllOfWithSingleRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Animal.java
index d4e4b98359f2..b71679ea8ba8 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Animal.java
@@ -149,10 +149,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 92dfa3a5b0f8..e7516ad8a693 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -115,10 +115,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index f66edec63b9e..a744db27f0c5 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -115,10 +115,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ArrayTest.java
index ee4dad24b790..3787d7d5b68f 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -197,10 +197,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Capitalization.java
index 1457016d97d5..039edb8c8cc1 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -268,10 +268,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Cat.java
index 033fec5b7082..042517026653 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Cat.java
@@ -129,10 +129,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder extends Animal.Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Category.java
index 755654bbcbb8..113cc2a4d120 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Category.java
@@ -136,10 +136,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 74fc3db81d90..6fde1d6e0b3b 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -141,10 +141,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder extends ParentWithNullable.Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ClassModel.java
index a68440e3339f..94325616298a 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -103,10 +103,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Client.java
index 6a65f07bfb0a..fb721b6117c6 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Client.java
@@ -103,10 +103,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index f7e6fd9c5dd6..77e72fefb9f6 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -105,10 +105,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Dog.java
index d802c438e5ea..5b24ffa6b656 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Dog.java
@@ -129,10 +129,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder extends Animal.Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/EnumArrays.java
index 34e7fd7f86d9..65462524cf3a 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -217,10 +217,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/EnumTest.java
index 897de79a2600..9b1084b99866 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -506,10 +506,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index 55d181b2e82b..0f86d1cc5ee9 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -148,10 +148,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index d897638edb2d..9f4f449e9809 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -148,10 +148,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Foo.java
index bf1691985eac..032589e0dc4f 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Foo.java
@@ -103,10 +103,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index 91f8ab20dd00..e818df353aee 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -105,10 +105,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/FormatTest.java
index c39d2a7b300e..e254ce20e2c1 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -614,10 +614,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index d1c1e8125b9e..81efd5801f7d 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -119,10 +119,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index b60876455ac2..de37430e6e2c 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -126,10 +126,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/MapTest.java
index 661853b47719..1c987c4aa833 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/MapTest.java
@@ -271,10 +271,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index ef1a2bede80f..6cc96429dd39 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -182,10 +182,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Model200Response.java
index 485cf38b0232..e2e622cb550c 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -137,10 +137,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 0f26f7946150..ccbf205d02cd 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -170,10 +170,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ModelFile.java
index e761d661fb51..37f87d923b9b 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -104,10 +104,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ModelList.java
index f49789ef2f65..d4ce2b9adfa5 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ModelList.java
@@ -104,10 +104,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ModelReturn.java
index fe71cce42682..8b1a7f782054 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -104,10 +104,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Name.java
index a2ffc26b1f82..c0f7e88f85b3 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Name.java
@@ -192,10 +192,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/NullableClass.java
index 3a92822706a3..39b292d1cda8 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -682,10 +682,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/NumberOnly.java
index df8b45485693..13564e7dd673 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -104,10 +104,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 60f19badb668..a491b4d4a2f0 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -221,10 +221,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Order.java
index cd1c847de71a..4150fa9f1e4c 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Order.java
@@ -306,10 +306,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/OuterComposite.java
index 8ebfc97a7e67..c602b296ead9 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -170,10 +170,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index eeae9c08472c..8ee0e81d9c0f 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -104,10 +104,7 @@ public class OuterObjectWithEnumProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index d948e2f6f727..87396a9d6390 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -204,10 +204,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Pet.java
index a5c907fabb6c..fa93ab49b7dd 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Pet.java
@@ -330,10 +330,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index cc8107112b2f..1c104c8d5245 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -135,10 +135,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/SpecialModelName.java
index 90d5763f9b47..76e090f3298c 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -104,10 +104,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Tag.java
index 7b536dcaaef1..09894e851301 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/Tag.java
@@ -136,10 +136,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index cd66d11ac1ea..c2940fcb0163 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -153,10 +153,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/User.java
index d9eeccebf02c..f8506bf1bfa3 100644
--- a/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/model/User.java
@@ -334,10 +334,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   public static class Builder {
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
index e3972b2debac..4d30760bb32b 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
@@ -139,10 +139,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
index b1f7bec9da55..6636bf059c42 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
@@ -140,10 +140,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
index cd9be7f3c97f..e9707fc66208 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
@@ -139,10 +139,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index e99b87939977..d02e2107f644 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -501,10 +501,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
index 087452ae35f3..d8470b335ed0 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
@@ -139,10 +139,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
index edf74877183d..4fc22ba776e7 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
@@ -140,10 +140,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
index 0b512113a835..892f44d81069 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
@@ -139,10 +139,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
index f230a09a4a6d..0f14f9d0cde2 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
@@ -139,10 +139,7 @@ public class AdditionalPropertiesString extends HashMap<String, String> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Animal.java
index aea28f644602..3c9c8767266e 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Animal.java
@@ -146,10 +146,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index a0dbff7d5de6..4609c0dbbaf7 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -111,10 +111,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 09d1c1f695eb..f591f3c78461 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -111,10 +111,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayTest.java
index 7cef9f9cd2f1..b3e8cef71053 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -194,10 +194,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/BigCat.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/BigCat.java
index ced6d93369e5..5b0f1a657ede 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/BigCat.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/BigCat.java
@@ -162,10 +162,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Capitalization.java
index 95744e121456..d778962f051e 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -263,10 +263,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Cat.java
index e6de542cc247..f8d319714311 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Cat.java
@@ -126,10 +126,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Category.java
index 2c6e65a0ffb2..7aff38e260cb 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Category.java
@@ -132,10 +132,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ClassModel.java
index 457f1c76e3ed..29f0ef3ab8e1 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -98,10 +98,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Client.java
index e22d41494242..e151d1cbddca 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Client.java
@@ -98,10 +98,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Dog.java
index 49d79deac7fb..ef4724c2d9ce 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Dog.java
@@ -123,10 +123,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/EnumArrays.java
index d04b094e7079..039282195224 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -212,10 +212,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/EnumTest.java
index 58749e17d917..a55c2b41d705 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -378,10 +378,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 8c8c30cbeec6..d8a091d3002d 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -145,10 +145,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/FormatTest.java
index 7b12c7d4f93f..cd094195ab5d 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -553,10 +553,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 74eb5453a668..13d0c33c41fe 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -122,10 +122,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/MapTest.java
index e35ca1d4377c..8a5a4c41d1b8 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/MapTest.java
@@ -267,10 +267,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index a44d2381c5c2..8c95e04727ba 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -180,10 +180,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Model200Response.java
index 72aa5cbc0fe0..1509799e9db7 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -132,10 +132,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index f18f82ffff1e..b2fcb9fb5753 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -165,10 +165,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ModelFile.java
index e2d139b04678..4dbc4e2ec6d8 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -99,10 +99,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ModelList.java
index f6bc0c2fa138..57f11355e1e2 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ModelList.java
@@ -99,10 +99,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ModelReturn.java
index 87b980ba6123..3e15d328e293 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -99,10 +99,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Name.java
index d1a5345247a6..7dd5d85c6d7c 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Name.java
@@ -188,10 +188,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/NumberOnly.java
index a3a78e7e73f7..ef33893bcf2f 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -100,10 +100,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Order.java
index 77c7ca7b4b0c..43c1d4bf3e9a 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Order.java
@@ -302,10 +302,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/OuterComposite.java
index 151ab769a2e6..460ca0b986fa 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -166,10 +166,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Pet.java
index 1348c9fce8a0..80dbc2caff0f 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Pet.java
@@ -329,10 +329,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 60993cb14401..64568473aac0 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -130,10 +130,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/SpecialModelName.java
index a2144cca3a1e..dfe124e19a58 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -99,10 +99,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Tag.java
index 451a57cafb9e..23e3d8c90ba0 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Tag.java
@@ -131,10 +131,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/TypeHolderDefault.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
index 2271418cf365..aff8aab4a549 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
@@ -248,10 +248,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/TypeHolderExample.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/TypeHolderExample.java
index 22c0ef2babfe..6a6c846c849a 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/TypeHolderExample.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/TypeHolderExample.java
@@ -282,10 +282,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/User.java
index c206544935a9..e85ec13ef7c1 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/User.java
@@ -329,10 +329,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/XmlItem.java
index 7eb51feb3093..dfeb3249d954 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -1103,10 +1103,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
index 926f8eac4309..d23bf0ffdaa3 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
@@ -93,10 +93,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
index 2b177749a8d4..a2d5a8f03305 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
@@ -94,10 +94,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
index 0424efa7d4b5..717b1ac4567a 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
@@ -93,10 +93,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 22ed8e5936a8..183f0adacd44 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -436,10 +436,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
index 649ceccd0f13..e93534c88bac 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
@@ -93,10 +93,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
index bad4851ab4e7..6cfbfbce2e4a 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
@@ -94,10 +94,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
index 2632d49db1d8..11a1725baf85 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
@@ -93,10 +93,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
index cd313527c7a1..eea5e9407ecd 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
@@ -93,10 +93,7 @@ public class AdditionalPropertiesString extends HashMap<String, String> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Animal.java
index eb57a4736994..e4929b9331f4 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Animal.java
@@ -116,10 +116,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 66a3d86ac040..cb3d1a65713d 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -100,10 +100,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 13ba0c820f10..8b243d166bca 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -100,10 +100,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayTest.java
index 94b5644ec042..0f82e4011fc7 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -172,10 +172,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/BigCat.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/BigCat.java
index 92fc50169ce1..cefab7a95e65 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/BigCat.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/BigCat.java
@@ -155,10 +155,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Capitalization.java
index e37eab475848..cb8083af0452 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -228,10 +228,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Cat.java
index 113b180ff216..d2660ca437a7 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Cat.java
@@ -104,10 +104,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Category.java
index c3d2173c92d7..f01ccffe7850 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Category.java
@@ -116,10 +116,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ClassModel.java
index 2e460a51cb21..52a2e77f00a5 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -88,10 +88,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Client.java
index 5383a6438242..7c315d5e2b2c 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Client.java
@@ -88,10 +88,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Dog.java
index f1cabcf06bfd..86d73c05e644 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Dog.java
@@ -104,10 +104,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/EnumArrays.java
index 94963f281c57..1ef71ff1c34a 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -221,10 +221,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/EnumTest.java
index 2ed7f7519df3..ebf197a5d786 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -393,10 +393,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 3306f5681e1c..923011eb2524 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -128,10 +128,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/FormatTest.java
index 44ce8a8d655a..ccd6ca0c9558 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -467,10 +467,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index d40a52ab9ae3..c66538833b59 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -110,10 +110,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/MapTest.java
index 0eb341dfceab..30c94ad48359 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/MapTest.java
@@ -253,10 +253,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 262dced94409..9ab4f9b720c9 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -157,10 +157,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Model200Response.java
index 5a0f55b339d8..4cc2f5446928 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -116,10 +116,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 09a2c9110cdf..15b56c8ed6f6 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -144,10 +144,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ModelFile.java
index 290cad324ba9..9252afc6a3e2 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -88,10 +88,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ModelList.java
index d2463e3a1278..c2eb67d01e84 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ModelList.java
@@ -88,10 +88,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ModelReturn.java
index 74467900b016..924817ec09d6 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -88,10 +88,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Name.java
index a9f705d9bdb3..78ecbc47a65f 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Name.java
@@ -166,10 +166,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/NumberOnly.java
index 2b9663dcf629..a08ad98175d5 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -89,10 +89,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Order.java
index fc549c2f0540..ef5da9a2450b 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Order.java
@@ -278,10 +278,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/OuterComposite.java
index 0f935346bd3f..ffd1ca4b695d 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -145,10 +145,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Pet.java
index 7a26d725c8d1..1262ffe314c1 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Pet.java
@@ -300,10 +300,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 5b5f9677a80c..eb47766f4cbf 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -117,10 +117,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/SpecialModelName.java
index b268ab65d366..0e8150630ee7 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -88,10 +88,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Tag.java
index ede83ccf92ac..a09fac2afb14 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Tag.java
@@ -116,10 +116,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/TypeHolderDefault.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
index ab6faf8637c4..42946aad79d3 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
@@ -212,10 +212,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/TypeHolderExample.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/TypeHolderExample.java
index 81c1b425c692..9c7ede18dc1d 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/TypeHolderExample.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/TypeHolderExample.java
@@ -240,10 +240,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/User.java
index ee47bb544cd6..b14686795122 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/User.java
@@ -284,10 +284,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/XmlItem.java
index 6497d809b019..cee4fabf847b 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -948,10 +948,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
index 926f8eac4309..d23bf0ffdaa3 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
@@ -93,10 +93,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
index 2b177749a8d4..a2d5a8f03305 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
@@ -94,10 +94,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
index 0424efa7d4b5..717b1ac4567a 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
@@ -93,10 +93,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 22ed8e5936a8..183f0adacd44 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -436,10 +436,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
index 649ceccd0f13..e93534c88bac 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
@@ -93,10 +93,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
index bad4851ab4e7..6cfbfbce2e4a 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
@@ -94,10 +94,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
index 2632d49db1d8..11a1725baf85 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
@@ -93,10 +93,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
index cd313527c7a1..eea5e9407ecd 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
@@ -93,10 +93,7 @@ public class AdditionalPropertiesString extends HashMap<String, String> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Animal.java
index eb57a4736994..e4929b9331f4 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Animal.java
@@ -116,10 +116,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 66a3d86ac040..cb3d1a65713d 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -100,10 +100,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 13ba0c820f10..8b243d166bca 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -100,10 +100,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayTest.java
index 94b5644ec042..0f82e4011fc7 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -172,10 +172,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/BigCat.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/BigCat.java
index 92fc50169ce1..cefab7a95e65 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/BigCat.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/BigCat.java
@@ -155,10 +155,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Capitalization.java
index e37eab475848..cb8083af0452 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -228,10 +228,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Cat.java
index 113b180ff216..d2660ca437a7 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Cat.java
@@ -104,10 +104,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Category.java
index c3d2173c92d7..f01ccffe7850 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Category.java
@@ -116,10 +116,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ClassModel.java
index 2e460a51cb21..52a2e77f00a5 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -88,10 +88,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Client.java
index 5383a6438242..7c315d5e2b2c 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Client.java
@@ -88,10 +88,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Dog.java
index f1cabcf06bfd..86d73c05e644 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Dog.java
@@ -104,10 +104,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/EnumArrays.java
index 94963f281c57..1ef71ff1c34a 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -221,10 +221,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/EnumTest.java
index 2ed7f7519df3..ebf197a5d786 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -393,10 +393,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 3306f5681e1c..923011eb2524 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -128,10 +128,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/FormatTest.java
index 44ce8a8d655a..ccd6ca0c9558 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -467,10 +467,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index d40a52ab9ae3..c66538833b59 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -110,10 +110,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/MapTest.java
index 0eb341dfceab..30c94ad48359 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/MapTest.java
@@ -253,10 +253,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 262dced94409..9ab4f9b720c9 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -157,10 +157,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Model200Response.java
index 5a0f55b339d8..4cc2f5446928 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -116,10 +116,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 09a2c9110cdf..15b56c8ed6f6 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -144,10 +144,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ModelFile.java
index 290cad324ba9..9252afc6a3e2 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -88,10 +88,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ModelList.java
index d2463e3a1278..c2eb67d01e84 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ModelList.java
@@ -88,10 +88,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ModelReturn.java
index 74467900b016..924817ec09d6 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -88,10 +88,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Name.java
index a9f705d9bdb3..78ecbc47a65f 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Name.java
@@ -166,10 +166,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/NumberOnly.java
index 2b9663dcf629..a08ad98175d5 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -89,10 +89,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Order.java
index fc549c2f0540..ef5da9a2450b 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Order.java
@@ -278,10 +278,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/OuterComposite.java
index 0f935346bd3f..ffd1ca4b695d 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -145,10 +145,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Pet.java
index 7a26d725c8d1..1262ffe314c1 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Pet.java
@@ -300,10 +300,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 5b5f9677a80c..eb47766f4cbf 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -117,10 +117,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/SpecialModelName.java
index b268ab65d366..0e8150630ee7 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -88,10 +88,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Tag.java
index ede83ccf92ac..a09fac2afb14 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Tag.java
@@ -116,10 +116,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/TypeHolderDefault.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
index ab6faf8637c4..42946aad79d3 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
@@ -212,10 +212,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/TypeHolderExample.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/TypeHolderExample.java
index 81c1b425c692..9c7ede18dc1d 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/TypeHolderExample.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/TypeHolderExample.java
@@ -240,10 +240,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/User.java
index ee47bb544cd6..b14686795122 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/User.java
@@ -284,10 +284,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/XmlItem.java
index 6497d809b019..cee4fabf847b 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -948,10 +948,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
index 926f8eac4309..d23bf0ffdaa3 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
@@ -93,10 +93,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
index 2b177749a8d4..a2d5a8f03305 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
@@ -94,10 +94,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
index 0424efa7d4b5..717b1ac4567a 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
@@ -93,10 +93,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 22ed8e5936a8..183f0adacd44 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -436,10 +436,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
index 649ceccd0f13..e93534c88bac 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
@@ -93,10 +93,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
index bad4851ab4e7..6cfbfbce2e4a 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
@@ -94,10 +94,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
index 2632d49db1d8..11a1725baf85 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
@@ -93,10 +93,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
index cd313527c7a1..eea5e9407ecd 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
@@ -93,10 +93,7 @@ public class AdditionalPropertiesString extends HashMap<String, String> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Animal.java
index eb57a4736994..e4929b9331f4 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Animal.java
@@ -116,10 +116,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 66a3d86ac040..cb3d1a65713d 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -100,10 +100,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 13ba0c820f10..8b243d166bca 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -100,10 +100,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayTest.java
index 94b5644ec042..0f82e4011fc7 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -172,10 +172,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/BigCat.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/BigCat.java
index 92fc50169ce1..cefab7a95e65 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/BigCat.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/BigCat.java
@@ -155,10 +155,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Capitalization.java
index e37eab475848..cb8083af0452 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -228,10 +228,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Cat.java
index 113b180ff216..d2660ca437a7 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Cat.java
@@ -104,10 +104,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Category.java
index c3d2173c92d7..f01ccffe7850 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Category.java
@@ -116,10 +116,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ClassModel.java
index 2e460a51cb21..52a2e77f00a5 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -88,10 +88,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Client.java
index 5383a6438242..7c315d5e2b2c 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Client.java
@@ -88,10 +88,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Dog.java
index f1cabcf06bfd..86d73c05e644 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Dog.java
@@ -104,10 +104,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/EnumArrays.java
index 94963f281c57..1ef71ff1c34a 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -221,10 +221,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/EnumTest.java
index 2ed7f7519df3..ebf197a5d786 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -393,10 +393,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 3306f5681e1c..923011eb2524 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -128,10 +128,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/FormatTest.java
index 44ce8a8d655a..ccd6ca0c9558 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -467,10 +467,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index d40a52ab9ae3..c66538833b59 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -110,10 +110,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/MapTest.java
index 0eb341dfceab..30c94ad48359 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/MapTest.java
@@ -253,10 +253,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 262dced94409..9ab4f9b720c9 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -157,10 +157,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Model200Response.java
index 5a0f55b339d8..4cc2f5446928 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -116,10 +116,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 09a2c9110cdf..15b56c8ed6f6 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -144,10 +144,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ModelFile.java
index 290cad324ba9..9252afc6a3e2 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -88,10 +88,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ModelList.java
index d2463e3a1278..c2eb67d01e84 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ModelList.java
@@ -88,10 +88,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ModelReturn.java
index 74467900b016..924817ec09d6 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -88,10 +88,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Name.java
index a9f705d9bdb3..78ecbc47a65f 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Name.java
@@ -166,10 +166,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/NumberOnly.java
index 2b9663dcf629..a08ad98175d5 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -89,10 +89,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Order.java
index fc549c2f0540..ef5da9a2450b 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Order.java
@@ -278,10 +278,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/OuterComposite.java
index 0f935346bd3f..ffd1ca4b695d 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -145,10 +145,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Pet.java
index 7a26d725c8d1..1262ffe314c1 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Pet.java
@@ -300,10 +300,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 5b5f9677a80c..eb47766f4cbf 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -117,10 +117,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/SpecialModelName.java
index b268ab65d366..0e8150630ee7 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -88,10 +88,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Tag.java
index ede83ccf92ac..a09fac2afb14 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Tag.java
@@ -116,10 +116,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/TypeHolderDefault.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
index ab6faf8637c4..42946aad79d3 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
@@ -212,10 +212,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/TypeHolderExample.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/TypeHolderExample.java
index 81c1b425c692..9c7ede18dc1d 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/TypeHolderExample.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/TypeHolderExample.java
@@ -240,10 +240,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/User.java
index ee47bb544cd6..b14686795122 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/User.java
@@ -284,10 +284,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/XmlItem.java
index 6497d809b019..cee4fabf847b 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -948,10 +948,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
index 447d5f69ae38..6a29be81285c 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
@@ -136,10 +136,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
index 2983e410b129..91cb7ea80f44 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
@@ -137,10 +137,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
index aaddf57fe39a..02ecbeafddb7 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
@@ -136,10 +136,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 860bcc928ff0..22469fb9fb92 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -483,10 +483,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
index c33954a06ff4..0244b022ede0 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
@@ -136,10 +136,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
index 3d29a210c7be..e650999ab964 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
@@ -137,10 +137,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
index 39375d02f6b2..4699ea278abb 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
@@ -136,10 +136,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
index e79b53cafc38..78e9777e44c1 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
@@ -136,10 +136,7 @@ public class AdditionalPropertiesString extends HashMap<String, String> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Animal.java
index 0282c5ffdde7..fcbee7978638 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Animal.java
@@ -141,10 +141,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 05aae9025b11..f999a3281c91 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index a57ad8474113..f5df05c07d07 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayTest.java
index 3dfa034fec8c..0c22d54edea7 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -187,10 +187,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/BigCat.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/BigCat.java
index 32c6cdd95506..38e9d3f7b9ff 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/BigCat.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/BigCat.java
@@ -159,10 +159,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Capitalization.java
index b2db0dd9497c..96cb38ffbd3a 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -255,10 +255,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Cat.java
index 06750c1b7a5c..4af5a2846af5 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Cat.java
@@ -123,10 +123,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Category.java
index b06cb8f143e1..c56efa1b8a0b 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Category.java
@@ -127,10 +127,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ClassModel.java
index 025a660fb102..1403f962eb6b 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -95,10 +95,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Client.java
index f88005a259bb..45d082779ab1 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Client.java
@@ -95,10 +95,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Dog.java
index 3dd517f475d9..0095b95b0c7c 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Dog.java
@@ -120,10 +120,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/EnumArrays.java
index 9da3fa9a02a2..8dbd1f17a19f 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -208,10 +208,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/EnumTest.java
index cfa2ee140da7..8d41cb7c4a41 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -369,10 +369,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 6ed704664d75..308d71e3c0c7 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -139,10 +139,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/FormatTest.java
index db1fc512bd4d..403435333e89 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -527,10 +527,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 0a02e6ac5bd2..3abffcdb884c 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -118,10 +118,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/MapTest.java
index 10cbd3663bf0..7fb194942948 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/MapTest.java
@@ -260,10 +260,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 148ff9614e56..faa706c19210 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -172,10 +172,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Model200Response.java
index 0662306cdfba..f555afa8b655 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -128,10 +128,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index c953c34819d3..c80bdaaf8c77 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -160,10 +160,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ModelFile.java
index 715f1a5940a4..7cabeb1588a8 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -96,10 +96,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ModelList.java
index b8b0ff69d52b..068f29bcd09c 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ModelList.java
@@ -96,10 +96,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ModelReturn.java
index 3bdefdbe181b..a7c0f9214aa5 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -96,10 +96,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Name.java
index b1fc0834268c..75523ca8acc0 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Name.java
@@ -181,10 +181,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/NumberOnly.java
index 36d4f5cd0f62..de65f8c39a85 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -96,10 +96,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Order.java
index 7e5b39766e8f..642eccbc1384 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Order.java
@@ -293,10 +293,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/OuterComposite.java
index 2c9c2d8be38e..60c4a04e7dff 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -160,10 +160,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Pet.java
index 2fddb31d41f8..5681216244a3 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Pet.java
@@ -317,10 +317,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index b341198f23f4..a9faae1c3d41 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -126,10 +126,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/SpecialModelName.java
index a3340c31a0c4..e7e62b054e88 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -96,10 +96,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Tag.java
index 4a44520fada0..ceb3d1ed3036 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Tag.java
@@ -127,10 +127,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/TypeHolderDefault.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
index 8dde1ca504e9..1287f8590068 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
@@ -235,10 +235,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/TypeHolderExample.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/TypeHolderExample.java
index 96348a7f852c..4dd1c0b5d6b1 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/TypeHolderExample.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/TypeHolderExample.java
@@ -267,10 +267,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/User.java
index 8427dda3f605..c871f7cb2a2f 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/User.java
@@ -319,10 +319,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/XmlItem.java
index 0777259cafe1..6d5959651f2d 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -1067,10 +1067,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index ca22cd6e8c92..1c400a0636c9 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -145,10 +145,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 6fc838649a61..ff6881338a4b 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -128,10 +128,7 @@ public class AllOfWithSingleRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Animal.java
index 0b680e4a8098..112c0fb4e844 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Animal.java
@@ -140,10 +140,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 05aae9025b11..f999a3281c91 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index a57ad8474113..f5df05c07d07 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ArrayTest.java
index 3dfa034fec8c..0c22d54edea7 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -187,10 +187,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Capitalization.java
index b2db0dd9497c..96cb38ffbd3a 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -255,10 +255,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Cat.java
index d71faa40c12d..692f5d965f3d 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Cat.java
@@ -120,10 +120,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Category.java
index b06cb8f143e1..c56efa1b8a0b 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Category.java
@@ -127,10 +127,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 1fcd981e18c5..812336c278c3 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -132,10 +132,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ClassModel.java
index 025a660fb102..1403f962eb6b 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -95,10 +95,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Client.java
index f88005a259bb..45d082779ab1 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Client.java
@@ -95,10 +95,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 24c7e5e5ddef..a8bb6ff86252 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -97,10 +97,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Dog.java
index 3dd517f475d9..0095b95b0c7c 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Dog.java
@@ -120,10 +120,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/EnumArrays.java
index 9da3fa9a02a2..8dbd1f17a19f 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -208,10 +208,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/EnumTest.java
index a9b99f7f7221..fc198e317b46 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -491,10 +491,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index f6da99504d3c..d28440acf3b0 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -139,10 +139,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 6ed704664d75..308d71e3c0c7 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -139,10 +139,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Foo.java
index 91253b36f172..c2f49aed150f 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Foo.java
@@ -95,10 +95,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index c2b9015e9db8..ac5fce79dae8 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -97,10 +97,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/FormatTest.java
index e5440f5c23f4..5ad850330bd1 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -591,10 +591,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 0a02e6ac5bd2..3abffcdb884c 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -118,10 +118,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index f9379a3b20fe..dd6054080b63 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -118,10 +118,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/MapTest.java
index 10cbd3663bf0..7fb194942948 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/MapTest.java
@@ -260,10 +260,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 148ff9614e56..faa706c19210 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -172,10 +172,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Model200Response.java
index 0662306cdfba..f555afa8b655 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -128,10 +128,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index c953c34819d3..c80bdaaf8c77 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -160,10 +160,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ModelFile.java
index 715f1a5940a4..7cabeb1588a8 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -96,10 +96,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ModelList.java
index b8b0ff69d52b..068f29bcd09c 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ModelList.java
@@ -96,10 +96,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ModelReturn.java
index 3bdefdbe181b..a7c0f9214aa5 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -96,10 +96,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Name.java
index b1fc0834268c..75523ca8acc0 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Name.java
@@ -181,10 +181,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/NullableClass.java
index 28b41e8da114..e54f4e219e6b 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -653,10 +653,7 @@ public class NullableClass extends HashMap<String, Object> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/NumberOnly.java
index 36d4f5cd0f62..de65f8c39a85 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -96,10 +96,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 63665bf5074c..0f70ada5df86 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -210,10 +210,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Order.java
index 7e5b39766e8f..642eccbc1384 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Order.java
@@ -293,10 +293,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/OuterComposite.java
index 2c9c2d8be38e..60c4a04e7dff 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -160,10 +160,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 675efcca5779..a06953c57d37 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -96,10 +96,7 @@ public class OuterObjectWithEnumProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index bd1d047e86df..8d532ba19c89 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -195,10 +195,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Pet.java
index 2fddb31d41f8..5681216244a3 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Pet.java
@@ -317,10 +317,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index b341198f23f4..a9faae1c3d41 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -126,10 +126,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/SpecialModelName.java
index aba001bad4a2..ba4d6f65b975 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -96,10 +96,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Tag.java
index 4a44520fada0..ceb3d1ed3036 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/Tag.java
@@ -127,10 +127,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 45896a5b4a23..e10cb3bfd43f 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -137,10 +137,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/User.java
index 8427dda3f605..c871f7cb2a2f 100644
--- a/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/vertx-supportVertxFuture/src/main/java/org/openapitools/client/model/User.java
@@ -319,10 +319,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index ca22cd6e8c92..1c400a0636c9 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -145,10 +145,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 6fc838649a61..ff6881338a4b 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -128,10 +128,7 @@ public class AllOfWithSingleRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Animal.java
index 0b680e4a8098..112c0fb4e844 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Animal.java
@@ -140,10 +140,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 05aae9025b11..f999a3281c91 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index a57ad8474113..f5df05c07d07 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayTest.java
index 3dfa034fec8c..0c22d54edea7 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -187,10 +187,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Capitalization.java
index b2db0dd9497c..96cb38ffbd3a 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -255,10 +255,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Cat.java
index d71faa40c12d..692f5d965f3d 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Cat.java
@@ -120,10 +120,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Category.java
index b06cb8f143e1..c56efa1b8a0b 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Category.java
@@ -127,10 +127,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 1fcd981e18c5..812336c278c3 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -132,10 +132,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ClassModel.java
index 025a660fb102..1403f962eb6b 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -95,10 +95,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Client.java
index f88005a259bb..45d082779ab1 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Client.java
@@ -95,10 +95,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 24c7e5e5ddef..a8bb6ff86252 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -97,10 +97,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Dog.java
index 3dd517f475d9..0095b95b0c7c 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Dog.java
@@ -120,10 +120,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/EnumArrays.java
index 9da3fa9a02a2..8dbd1f17a19f 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -208,10 +208,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/EnumTest.java
index a9b99f7f7221..fc198e317b46 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -491,10 +491,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index f6da99504d3c..d28440acf3b0 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -139,10 +139,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 6ed704664d75..308d71e3c0c7 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -139,10 +139,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Foo.java
index 91253b36f172..c2f49aed150f 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Foo.java
@@ -95,10 +95,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index c2b9015e9db8..ac5fce79dae8 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -97,10 +97,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FormatTest.java
index e5440f5c23f4..5ad850330bd1 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -591,10 +591,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 0a02e6ac5bd2..3abffcdb884c 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -118,10 +118,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index f9379a3b20fe..dd6054080b63 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -118,10 +118,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/MapTest.java
index 10cbd3663bf0..7fb194942948 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/MapTest.java
@@ -260,10 +260,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 148ff9614e56..faa706c19210 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -172,10 +172,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Model200Response.java
index 0662306cdfba..f555afa8b655 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -128,10 +128,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index c953c34819d3..c80bdaaf8c77 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -160,10 +160,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ModelFile.java
index 715f1a5940a4..7cabeb1588a8 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -96,10 +96,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ModelList.java
index b8b0ff69d52b..068f29bcd09c 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ModelList.java
@@ -96,10 +96,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ModelReturn.java
index 3bdefdbe181b..a7c0f9214aa5 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -96,10 +96,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Name.java
index b1fc0834268c..75523ca8acc0 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Name.java
@@ -181,10 +181,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/NullableClass.java
index 28b41e8da114..e54f4e219e6b 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -653,10 +653,7 @@ public class NullableClass extends HashMap<String, Object> {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/NumberOnly.java
index 36d4f5cd0f62..de65f8c39a85 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -96,10 +96,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 63665bf5074c..0f70ada5df86 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -210,10 +210,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Order.java
index 7e5b39766e8f..642eccbc1384 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Order.java
@@ -293,10 +293,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/OuterComposite.java
index 2c9c2d8be38e..60c4a04e7dff 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -160,10 +160,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 675efcca5779..a06953c57d37 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -96,10 +96,7 @@ public class OuterObjectWithEnumProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index bd1d047e86df..8d532ba19c89 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -195,10 +195,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Pet.java
index 2fddb31d41f8..5681216244a3 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Pet.java
@@ -317,10 +317,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index b341198f23f4..a9faae1c3d41 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -126,10 +126,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/SpecialModelName.java
index aba001bad4a2..ba4d6f65b975 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -96,10 +96,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Tag.java
index 4a44520fada0..ceb3d1ed3036 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Tag.java
@@ -127,10 +127,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 45896a5b4a23..e10cb3bfd43f 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -137,10 +137,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/User.java
index 8427dda3f605..c871f7cb2a2f 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/User.java
@@ -319,10 +319,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 16bd79b46a9e..59d3f8ea668b 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -145,10 +145,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index ba06830e3438..d7fe4e337669 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -128,10 +128,7 @@ public class AllOfWithSingleRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Animal.java
index be73b77eb56b..3eee92a9cbf1 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Animal.java
@@ -140,10 +140,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 704d34455f65..4a482317c3a9 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 60340b875152..aad9a5df35a4 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayTest.java
index fc4d5b3e8c61..e630a4730fc9 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -187,10 +187,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Capitalization.java
index 59c9887ace81..99bdb244771c 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -255,10 +255,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Cat.java
index c5202d64b0d8..c3824083616c 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Cat.java
@@ -120,10 +120,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Category.java
index dcbf3b28eec3..b5f41d6759fd 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Category.java
@@ -127,10 +127,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 71f5d9315398..2fe00c58823d 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -132,10 +132,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ClassModel.java
index ae1f21522f76..ef5aeb3d1d9a 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -95,10 +95,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Client.java
index 2d41fd3b98f1..d034c93f461d 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Client.java
@@ -95,10 +95,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 458eced04103..703b45871a3f 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -97,10 +97,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Dog.java
index e52083a68417..12caf87bce07 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Dog.java
@@ -120,10 +120,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/EnumArrays.java
index 257a81444b64..3de47308db25 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -208,10 +208,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/EnumTest.java
index a19ce0c0bc87..1163dd57a279 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -491,10 +491,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index 7d14078a676f..e80ecfed5d75 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -139,10 +139,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 7b897789b27a..46a92812641c 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -139,10 +139,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Foo.java
index 1a436bc47b35..4714273c5486 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Foo.java
@@ -95,10 +95,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index 27b2f1dd4520..afbd0782bfde 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -97,10 +97,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FormatTest.java
index ee80458c5c61..8505436b835c 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -591,10 +591,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index ff53f25a3556..5cc80147290e 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -118,10 +118,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 1c61edd8287d..cdc849c139d3 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -118,10 +118,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/MapTest.java
index 1e86ddb235e9..f5ec58eac091 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/MapTest.java
@@ -260,10 +260,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index c3d201933159..2d2fe0cd0ce3 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -172,10 +172,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Model200Response.java
index 3c96ed71a6dd..c80c3f966f6d 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -128,10 +128,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 192ce8ac2c4e..13db33fd5215 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -160,10 +160,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ModelFile.java
index d32665d2843e..ad5d79cd516d 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -96,10 +96,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ModelList.java
index 37dd385c227e..b211eab553be 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ModelList.java
@@ -96,10 +96,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ModelReturn.java
index b28893996b31..d236da175a39 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -96,10 +96,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Name.java
index 97c78a771fbe..5f2aa0391f8a 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Name.java
@@ -181,10 +181,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/NullableClass.java
index 03d00e0217d5..532c0265e320 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -663,10 +663,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/NumberOnly.java
index 726536f0de7b..a71400caa916 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -96,10 +96,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 6e0bd497a669..239e5321ded3 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -210,10 +210,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Order.java
index dc17de8625d4..01e2fabc9e80 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Order.java
@@ -293,10 +293,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/OuterComposite.java
index d5d7e84f690e..ba1f6f88cbd1 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -160,10 +160,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index fd8ebf0cb4fb..88e34731568d 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -96,10 +96,7 @@ public class OuterObjectWithEnumProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index b5c74a416648..66e11cfd428f 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -195,10 +195,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Pet.java
index c43d5536e42a..5d2d9f122592 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Pet.java
@@ -317,10 +317,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index f4d4dd7a65a5..200df1da921c 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -126,10 +126,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/SpecialModelName.java
index 223888f0d776..97ad09bebff8 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -96,10 +96,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Tag.java
index ee70bd6ce68a..093911c3f691 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Tag.java
@@ -127,10 +127,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 7cd0a64a728d..2b37c26b9368 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -145,10 +145,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/User.java
index 5b2939d45f85..61acb356334e 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/User.java
@@ -319,10 +319,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-nullable-arrays/src/main/java/org/openapitools/client/model/ByteArrayObject.java b/samples/client/petstore/java/webclient-nullable-arrays/src/main/java/org/openapitools/client/model/ByteArrayObject.java
index a867d0e84663..af23cccc70d9 100644
--- a/samples/client/petstore/java/webclient-nullable-arrays/src/main/java/org/openapitools/client/model/ByteArrayObject.java
+++ b/samples/client/petstore/java/webclient-nullable-arrays/src/main/java/org/openapitools/client/model/ByteArrayObject.java
@@ -255,10 +255,7 @@ public class ByteArrayObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/webclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Category.java
index 0ba3517c2265..74f645bcbe00 100644
--- a/samples/client/petstore/java/webclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/webclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Category.java
@@ -126,10 +126,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/webclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Pet.java
index 8502f31234c0..3bc5ba9193d7 100644
--- a/samples/client/petstore/java/webclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/webclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Pet.java
@@ -314,10 +314,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/webclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Tag.java
index ee81740af0a2..dacf71b31e51 100644
--- a/samples/client/petstore/java/webclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/webclient-springBoot4-jackson3/src/main/java/org/openapitools/client/model/Tag.java
@@ -126,10 +126,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 81b26e9752c7..3e29eca6b9f5 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -148,10 +148,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index cace7893094a..c2b7ea45a017 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -131,10 +131,7 @@ public class AllOfWithSingleRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Animal.java
index 3e55269efd69..b318b8eca908 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Animal.java
@@ -143,10 +143,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 7e81591b4e95..62a19f5b72fa 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -109,10 +109,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index cf9b475ab477..a6b3b258d4e2 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -109,10 +109,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ArrayTest.java
index e894a976722e..7b1ce9748efd 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -191,10 +191,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Capitalization.java
index f4e9a61983e5..71aed21498f3 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -262,10 +262,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Cat.java
index e8211aab6b0a..efda5e6890af 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Cat.java
@@ -122,10 +122,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Category.java
index 0b8e1b1d7591..1833430406e9 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Category.java
@@ -130,10 +130,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index bc52d4642eda..4ae0fddfbec2 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -134,10 +134,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ClassModel.java
index e7348173a7f5..a561b97dbb17 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -98,10 +98,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Client.java
index 5a2427c4121b..90d87ce8b5b7 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Client.java
@@ -97,10 +97,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 8f666a63405e..687a8379118a 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -99,10 +99,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Dog.java
index 9dd6b3c8a272..2186cad6e257 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Dog.java
@@ -122,10 +122,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/EnumArrays.java
index 432e45fb1449..f10402d47ade 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -211,10 +211,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/EnumTest.java
index abe9d99e00ed..bfb9bd99bb01 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -500,10 +500,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index dcef98bca618..ed870487920c 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -142,10 +142,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 5af8e2892e30..56a076b14332 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -142,10 +142,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Foo.java
index 9f4b4dd97a2f..896f5b921899 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Foo.java
@@ -97,10 +97,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index cce30507a398..941203c9dfbd 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -99,10 +99,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/FormatTest.java
index 0f2b513d8aea..c5f7d7628b9d 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -608,10 +608,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index a97bad413cba..3e6a70002949 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -121,10 +121,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index da48c23e59ec..f38ac2d50273 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -121,10 +121,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/MapTest.java
index 6078f6b153de..106824bbf93a 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/MapTest.java
@@ -265,10 +265,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 430e046bfcce..b54c850c7e6c 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -176,10 +176,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Model200Response.java
index beaf0eb73d2e..723e7b9e86d5 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -132,10 +132,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index d96db5e563e3..0508c2fff7ea 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -164,10 +164,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ModelFile.java
index c553921c85de..80cb3ad42eea 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -99,10 +99,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ModelList.java
index 8d69792e00b9..da301b99953f 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ModelList.java
@@ -98,10 +98,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ModelReturn.java
index 2cbffd729ac3..f0c5faebf5a0 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -99,10 +99,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Name.java
index c4aaf30b13b9..83ee9a5afc15 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Name.java
@@ -187,10 +187,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/NullableClass.java
index 5627efbca16c..6cbf53b52641 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -676,10 +676,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/NumberOnly.java
index d70ab9d0813b..3da22cabc637 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -98,10 +98,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index a58e6da652d4..b95ca2e9442d 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -215,10 +215,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Order.java
index 9624e88beb00..c866abad0482 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Order.java
@@ -300,10 +300,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/OuterComposite.java
index 1e49f44454b9..e8c2694b6c32 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -164,10 +164,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index d2abefc6cd5b..1bd4e9547ba9 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -98,10 +98,7 @@ public class OuterObjectWithEnumProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index 0eea7c1dba94..ea9172f8d4af 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -198,10 +198,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Pet.java
index 86862677c6e4..55c404402374 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Pet.java
@@ -324,10 +324,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 7e652539c889..9f5b47bff50b 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -129,10 +129,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/SpecialModelName.java
index 4e2c5cf6d3f2..8a80c63d9012 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -98,10 +98,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Tag.java
index b12c7cbedcd6..1e130e96c668 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/Tag.java
@@ -130,10 +130,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index ed8705e943f8..ea1cc96e2045 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -147,10 +147,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/User.java
index cdec81f017e8..6a6168cd7487 100644
--- a/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/webclient-swagger2/src/main/java/org/openapitools/client/model/User.java
@@ -328,10 +328,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index ca22cd6e8c92..1c400a0636c9 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -145,10 +145,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 6fc838649a61..ff6881338a4b 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -128,10 +128,7 @@ public class AllOfWithSingleRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Animal.java
index 0b680e4a8098..112c0fb4e844 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Animal.java
@@ -140,10 +140,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 05aae9025b11..f999a3281c91 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index a57ad8474113..f5df05c07d07 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayTest.java
index 3dfa034fec8c..0c22d54edea7 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -187,10 +187,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Capitalization.java
index b2db0dd9497c..96cb38ffbd3a 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -255,10 +255,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Cat.java
index d71faa40c12d..692f5d965f3d 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Cat.java
@@ -120,10 +120,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Category.java
index b06cb8f143e1..c56efa1b8a0b 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Category.java
@@ -127,10 +127,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 1fcd981e18c5..812336c278c3 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -132,10 +132,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ClassModel.java
index 025a660fb102..1403f962eb6b 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -95,10 +95,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Client.java
index f88005a259bb..45d082779ab1 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Client.java
@@ -95,10 +95,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 24c7e5e5ddef..a8bb6ff86252 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -97,10 +97,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Dog.java
index 3dd517f475d9..0095b95b0c7c 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Dog.java
@@ -120,10 +120,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/EnumArrays.java
index 9da3fa9a02a2..8dbd1f17a19f 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -208,10 +208,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/EnumTest.java
index d387fc60e394..68e0f7a9d065 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -491,10 +491,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index f6da99504d3c..d28440acf3b0 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -139,10 +139,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 6ed704664d75..308d71e3c0c7 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -139,10 +139,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Foo.java
index 91253b36f172..c2f49aed150f 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Foo.java
@@ -95,10 +95,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index c2b9015e9db8..ac5fce79dae8 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -97,10 +97,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FormatTest.java
index fe966603c8e2..5248ba73b78b 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -591,10 +591,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 28d329fa9903..8b1507807356 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -118,10 +118,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index cc6ae01413bb..909824bcf917 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -118,10 +118,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/MapTest.java
index 10cbd3663bf0..7fb194942948 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/MapTest.java
@@ -260,10 +260,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 148ff9614e56..faa706c19210 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -172,10 +172,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Model200Response.java
index 0662306cdfba..f555afa8b655 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -128,10 +128,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index c953c34819d3..c80bdaaf8c77 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -160,10 +160,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelFile.java
index 715f1a5940a4..7cabeb1588a8 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -96,10 +96,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelList.java
index b8b0ff69d52b..068f29bcd09c 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelList.java
@@ -96,10 +96,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelReturn.java
index 3bdefdbe181b..a7c0f9214aa5 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -96,10 +96,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Name.java
index d037ea466927..b236f7790dac 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Name.java
@@ -181,10 +181,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/NullableClass.java
index 6afe04dc9637..f4c13f09427c 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -663,10 +663,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/NumberOnly.java
index 36d4f5cd0f62..de65f8c39a85 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -96,10 +96,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 63665bf5074c..0f70ada5df86 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -210,10 +210,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Order.java
index 7e5b39766e8f..642eccbc1384 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Order.java
@@ -293,10 +293,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/OuterComposite.java
index 2c9c2d8be38e..60c4a04e7dff 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -160,10 +160,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 675efcca5779..a06953c57d37 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -96,10 +96,7 @@ public class OuterObjectWithEnumProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index 439829b1ad60..c1910b9d8bc0 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -195,10 +195,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Pet.java
index 2fddb31d41f8..5681216244a3 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Pet.java
@@ -317,10 +317,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 910a01838c87..dfe79f8192db 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -126,10 +126,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/SpecialModelName.java
index aba001bad4a2..ba4d6f65b975 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -96,10 +96,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Tag.java
index 4a44520fada0..ceb3d1ed3036 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/Tag.java
@@ -127,10 +127,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 47de6bbb5203..38a33f15e80a 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -145,10 +145,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/User.java
index 8427dda3f605..c871f7cb2a2f 100644
--- a/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/webclient-useSingleRequestParameter/src/main/java/org/openapitools/client/model/User.java
@@ -319,10 +319,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 4d7cb75462d8..d8984d471357 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -145,10 +145,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
index 6fc838649a61..ff6881338a4b 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/AllOfWithSingleRef.java
@@ -128,10 +128,7 @@ public class AllOfWithSingleRef {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Animal.java
index 0b680e4a8098..112c0fb4e844 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Animal.java
@@ -140,10 +140,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 227692921bb2..178d7b3e9acd 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 2249f6077e0b..8bd230a9dcfd 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -107,10 +107,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ArrayTest.java
index 804fa135d6f7..e806ab91fedf 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -187,10 +187,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Capitalization.java
index b2db0dd9497c..96cb38ffbd3a 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -255,10 +255,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Cat.java
index d71faa40c12d..692f5d965f3d 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Cat.java
@@ -120,10 +120,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Category.java
index b06cb8f143e1..c56efa1b8a0b 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Category.java
@@ -127,10 +127,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ChildWithNullable.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ChildWithNullable.java
index 1fcd981e18c5..812336c278c3 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ChildWithNullable.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ChildWithNullable.java
@@ -132,10 +132,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ClassModel.java
index 025a660fb102..1403f962eb6b 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -95,10 +95,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Client.java
index f88005a259bb..45d082779ab1 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Client.java
@@ -95,10 +95,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 24c7e5e5ddef..a8bb6ff86252 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -97,10 +97,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Dog.java
index 3dd517f475d9..0095b95b0c7c 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Dog.java
@@ -120,10 +120,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/EnumArrays.java
index 878ed036a224..33a1bbc96a92 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -208,10 +208,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/EnumTest.java
index d387fc60e394..68e0f7a9d065 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -491,10 +491,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
index 67aadd1772e4..c27aa72b8d12 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/FakeBigDecimalMap200Response.java
@@ -139,10 +139,7 @@ public class FakeBigDecimalMap200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index eae72b2a9fa4..74f5b8359920 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -139,10 +139,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Foo.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Foo.java
index 91253b36f172..c2f49aed150f 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Foo.java
@@ -95,10 +95,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index c2b9015e9db8..ac5fce79dae8 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -97,10 +97,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/FormatTest.java
index fe966603c8e2..5248ba73b78b 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -591,10 +591,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 28d329fa9903..8b1507807356 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -118,10 +118,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index cc6ae01413bb..909824bcf917 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -118,10 +118,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/MapTest.java
index d091d8f26793..8ea93d530683 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/MapTest.java
@@ -260,10 +260,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 53083ca1fb59..4d235606cedf 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -172,10 +172,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Model200Response.java
index 0662306cdfba..f555afa8b655 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -128,10 +128,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index c953c34819d3..c80bdaaf8c77 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -160,10 +160,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ModelFile.java
index 715f1a5940a4..7cabeb1588a8 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -96,10 +96,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ModelList.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ModelList.java
index b8b0ff69d52b..068f29bcd09c 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ModelList.java
@@ -96,10 +96,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ModelReturn.java
index 3bdefdbe181b..a7c0f9214aa5 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -96,10 +96,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Name.java
index d037ea466927..b236f7790dac 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Name.java
@@ -181,10 +181,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/NullableClass.java
index 0392d2f8a061..147ba3be835e 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -663,10 +663,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/NumberOnly.java
index 36d4f5cd0f62..de65f8c39a85 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -96,10 +96,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 2e56432ec34c..1b5f194b36c6 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -210,10 +210,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Order.java
index 7e5b39766e8f..642eccbc1384 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Order.java
@@ -293,10 +293,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/OuterComposite.java
index 2c9c2d8be38e..60c4a04e7dff 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -160,10 +160,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
index 675efcca5779..a06953c57d37 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/OuterObjectWithEnumProperty.java
@@ -96,10 +96,7 @@ public class OuterObjectWithEnumProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ParentWithNullable.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ParentWithNullable.java
index 439829b1ad60..c1910b9d8bc0 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ParentWithNullable.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ParentWithNullable.java
@@ -195,10 +195,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Pet.java
index a792163bafa4..20e63dc4b6ab 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Pet.java
@@ -317,10 +317,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 910a01838c87..dfe79f8192db 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -126,10 +126,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/SpecialModelName.java
index aba001bad4a2..ba4d6f65b975 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -96,10 +96,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Tag.java
index 4a44520fada0..ceb3d1ed3036 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Tag.java
@@ -127,10 +127,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 47de6bbb5203..38a33f15e80a 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -145,10 +145,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/User.java
index 8427dda3f605..c871f7cb2a2f 100644
--- a/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/User.java
@@ -319,10 +319,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/Category.java b/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/Category.java
index 55629a6ed0b9..ff90bc40bc35 100644
--- a/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/Category.java
@@ -90,10 +90,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/ModelApiResponse.java
index b83dd190195b..0da15b474943 100644
--- a/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -115,10 +115,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/Order.java b/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/Order.java
index dd138eac3273..5765180bea89 100644
--- a/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/Order.java
@@ -227,10 +227,7 @@ PLACED(String.valueOf("placed")), APPROVED(String.valueOf("approved")), DELIVERE
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/Pet.java b/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/Pet.java
index ca5a35c0ee02..fe1d8c678acc 100644
--- a/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/Pet.java
@@ -241,10 +241,7 @@ AVAILABLE(String.valueOf("available")), PENDING(String.valueOf("pending")), SOLD
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/Tag.java b/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/Tag.java
index 81b61d461cfe..11f65cb3dc73 100644
--- a/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/Tag.java
@@ -90,10 +90,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/User.java b/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/User.java
index a27f47d99ce5..c8be0e76b14f 100644
--- a/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/User.java
+++ b/samples/client/petstore/jaxrs-cxf-client-jackson/src/gen/java/org/openapitools/model/User.java
@@ -237,10 +237,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/Category.java b/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/Category.java
index b87fe5924435..7751b4716acd 100644
--- a/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/Category.java
@@ -89,10 +89,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/ModelApiResponse.java
index fa490f33f000..68132365e828 100644
--- a/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -113,10 +113,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/Order.java b/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/Order.java
index cc6bfed1644d..0fa164af4d9e 100644
--- a/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/Order.java
@@ -222,10 +222,7 @@ PLACED(String.valueOf("placed")), APPROVED(String.valueOf("approved")), DELIVERE
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/Pet.java b/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/Pet.java
index 49c860b8bc1e..16235b9df7c5 100644
--- a/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/Pet.java
@@ -236,10 +236,7 @@ AVAILABLE(String.valueOf("available")), PENDING(String.valueOf("pending")), SOLD
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/Tag.java b/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/Tag.java
index 2d6aa396bc08..323d44bae955 100644
--- a/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/Tag.java
@@ -89,10 +89,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/User.java b/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/User.java
index a26d89d5f60b..95a669ce1bdc 100644
--- a/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/User.java
+++ b/samples/client/petstore/jaxrs-cxf-client-swagger2/src/gen/java/org/openapitools/model/User.java
@@ -236,10 +236,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/Category.java b/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/Category.java
index 55629a6ed0b9..ff90bc40bc35 100644
--- a/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/Category.java
@@ -90,10 +90,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/ModelApiResponse.java
index 85573619906a..299c44957e72 100644
--- a/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -114,10 +114,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/Order.java b/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/Order.java
index e7c2d133029e..3a479cb74895 100644
--- a/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/Order.java
@@ -223,10 +223,7 @@ PLACED(String.valueOf("placed")), APPROVED(String.valueOf("approved")), DELIVERE
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/Pet.java b/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/Pet.java
index 4ae1c9043be0..5a6525d79c4c 100644
--- a/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/Pet.java
@@ -237,10 +237,7 @@ AVAILABLE(String.valueOf("available")), PENDING(String.valueOf("pending")), SOLD
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/Tag.java b/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/Tag.java
index 81b61d461cfe..11f65cb3dc73 100644
--- a/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/Tag.java
@@ -90,10 +90,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/User.java b/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/User.java
index a27f47d99ce5..c8be0e76b14f 100644
--- a/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/User.java
+++ b/samples/client/petstore/jaxrs-cxf-client/src/gen/java/org/openapitools/model/User.java
@@ -237,10 +237,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-date-time/src/main/java/org/openapitools/model/Pet.java b/samples/client/petstore/spring-cloud-date-time/src/main/java/org/openapitools/model/Pet.java
index 3d7480556507..35f411500d3b 100644
--- a/samples/client/petstore/spring-cloud-date-time/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/client/petstore/spring-cloud-date-time/src/main/java/org/openapitools/model/Pet.java
@@ -219,10 +219,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Category.java b/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Category.java
index a83df46e1b37..24b392308f53 100644
--- a/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Category.java
+++ b/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Category.java
@@ -102,10 +102,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/ModelApiResponse.java
index fd3c591671e8..edeb1f66019e 100644
--- a/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Order.java b/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Order.java
index 0240d7928f73..81c69d33b1ae 100644
--- a/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Order.java
+++ b/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Order.java
@@ -245,10 +245,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Pet.java b/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Pet.java
index ae597443ffc9..07c6e38aa52c 100644
--- a/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Pet.java
@@ -282,10 +282,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Tag.java b/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Tag.java
index f8a38e352878..1f94a8ef63aa 100644
--- a/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/User.java b/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/User.java
index 4e55c123cbf5..ae9bf7482766 100644
--- a/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/User.java
+++ b/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Category.java b/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Category.java
index 1d01e6dcae87..04a37147726e 100644
--- a/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Category.java
+++ b/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Category.java
@@ -103,10 +103,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/ModelApiResponse.java
index 95a3f47ca35a..1012a5a2bdb3 100644
--- a/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -130,10 +130,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Order.java b/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Order.java
index 7b91efd30b55..fefd64b7bf9c 100644
--- a/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Order.java
+++ b/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Order.java
@@ -244,10 +244,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Pet.java b/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Pet.java
index 35d21245ffdc..5c87f13202bf 100644
--- a/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Pet.java
@@ -283,10 +283,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Tag.java b/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Tag.java
index b79c22d00978..34510604ee4d 100644
--- a/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Tag.java
@@ -103,10 +103,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/User.java b/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/User.java
index 5848bbdbc6fd..c93944d5ea2e 100644
--- a/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/User.java
+++ b/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/User.java
@@ -253,10 +253,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Category.java b/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Category.java
index e1a6914c667e..8959a86fd679 100644
--- a/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Category.java
+++ b/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Category.java
@@ -103,10 +103,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/ModelApiResponse.java
index 95a3f47ca35a..1012a5a2bdb3 100644
--- a/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -130,10 +130,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Order.java b/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Order.java
index 7b91efd30b55..fefd64b7bf9c 100644
--- a/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Order.java
+++ b/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Order.java
@@ -244,10 +244,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Pet.java b/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Pet.java
index b579e0f6b6db..16bb5cc9d495 100644
--- a/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Pet.java
@@ -276,10 +276,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Tag.java b/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Tag.java
index b79c22d00978..34510604ee4d 100644
--- a/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Tag.java
@@ -103,10 +103,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/User.java b/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/User.java
index 5848bbdbc6fd..c93944d5ea2e 100644
--- a/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/User.java
+++ b/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/User.java
@@ -253,10 +253,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Category.java b/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Category.java
index 1d01e6dcae87..04a37147726e 100644
--- a/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Category.java
+++ b/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Category.java
@@ -103,10 +103,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/ModelApiResponse.java
index 95a3f47ca35a..1012a5a2bdb3 100644
--- a/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -130,10 +130,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Order.java b/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Order.java
index 7b91efd30b55..fefd64b7bf9c 100644
--- a/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Order.java
+++ b/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Order.java
@@ -244,10 +244,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Pet.java b/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Pet.java
index 35d21245ffdc..5c87f13202bf 100644
--- a/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Pet.java
@@ -283,10 +283,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Tag.java b/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Tag.java
index b79c22d00978..34510604ee4d 100644
--- a/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Tag.java
@@ -103,10 +103,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/User.java b/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/User.java
index 5848bbdbc6fd..c93944d5ea2e 100644
--- a/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/User.java
+++ b/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/User.java
@@ -253,10 +253,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java
index 5937c453e782..2611d3478847 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java
@@ -119,10 +119,7 @@ public class AdditionalPropertiesAnyTypeDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java
index dc20cbc33cdc..730aaf70ddab 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesArrayDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java
index 91310ef26bbf..cad28f5c1ce5 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java
@@ -119,10 +119,7 @@ public class AdditionalPropertiesBooleanDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
index c7ed595a5f15..bd8116825e06 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
@@ -404,10 +404,7 @@ public class AdditionalPropertiesClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java
index 32e1bc6b62a0..080a7851ef71 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java
@@ -119,10 +119,7 @@ public class AdditionalPropertiesIntegerDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java
index f8e8b94e7818..85709bac7c15 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesNumberDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java
index a1d840719628..c18f89761ce3 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesObjectDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java
index eb8a7e29d379..aa6651892dd5 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java
@@ -119,10 +119,7 @@ public class AdditionalPropertiesStringDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AnimalDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AnimalDto.java
index 943f1720c72c..a7828db1f81f 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AnimalDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/AnimalDto.java
@@ -116,10 +116,7 @@ public class AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ApiResponseDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ApiResponseDto.java
index ef8534255191..923775dc1bdb 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ApiResponseDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ApiResponseDto.java
@@ -123,10 +123,7 @@ public class ApiResponseDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
index 6572d7c4e8a7..322c7d51d232 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
@@ -88,10 +88,7 @@ public class ArrayOfArrayOfNumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
index 84f58748abe4..e554dec5aeb6 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
@@ -88,10 +88,7 @@ public class ArrayOfNumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ArrayTestDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ArrayTestDto.java
index e3def2e1fee1..9c6ab174ff14 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ArrayTestDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ArrayTestDto.java
@@ -154,10 +154,7 @@ public class ArrayTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/BigCatDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/BigCatDto.java
index 2de6bd531601..4cd6531fb1e7 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/BigCatDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/BigCatDto.java
@@ -141,10 +141,7 @@ public class BigCatDto extends CatDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/CapitalizationDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/CapitalizationDto.java
index 2a903a38fb67..e96926a07cfc 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/CapitalizationDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/CapitalizationDto.java
@@ -195,10 +195,7 @@ public class CapitalizationDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/CatDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/CatDto.java
index be24b518bbe9..88fbb22d8dbc 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/CatDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/CatDto.java
@@ -103,10 +103,7 @@ public class CatDto extends AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/CategoryDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/CategoryDto.java
index 9c13015b88f3..78f9b53f3359 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/CategoryDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/CategoryDto.java
@@ -103,10 +103,7 @@ public class CategoryDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ChildWithNullableDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ChildWithNullableDto.java
index 06f87e68f756..5500608d7521 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ChildWithNullableDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ChildWithNullableDto.java
@@ -106,10 +106,7 @@ public class ChildWithNullableDto extends ParentWithNullableDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ClassModelDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ClassModelDto.java
index 3de34bbd21f1..28d87018088a 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ClassModelDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ClassModelDto.java
@@ -75,10 +75,7 @@ public class ClassModelDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ClientDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ClientDto.java
index d933a0917e9c..44007998434b 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ClientDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ClientDto.java
@@ -75,10 +75,7 @@ public class ClientDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java
index 7390b1716da2..5fb6cea84bae 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java
@@ -201,10 +201,7 @@ public class ContainerDefaultValueDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/DogDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/DogDto.java
index a907ccf2e4b8..a8b326626e91 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/DogDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/DogDto.java
@@ -96,10 +96,7 @@ public class DogDto extends AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/EnumArraysDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/EnumArraysDto.java
index e69a98c73299..6b6cc2ffb304 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/EnumArraysDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/EnumArraysDto.java
@@ -182,10 +182,7 @@ public class EnumArraysDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/EnumTestDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/EnumTestDto.java
index fb94f5ce13fb..b99a01c6d0aa 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/EnumTestDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/EnumTestDto.java
@@ -321,10 +321,7 @@ public class EnumTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/FileDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/FileDto.java
index b17eed66258b..741bd42b27b0 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/FileDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/FileDto.java
@@ -75,10 +75,7 @@ public class FileDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
index 28763bdeaffd..d6a0651a7953 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
@@ -112,10 +112,7 @@ public class FileSchemaTestClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/FormatTestDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/FormatTestDto.java
index 4d8206d4a198..9699dd2c4298 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/FormatTestDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/FormatTestDto.java
@@ -409,10 +409,7 @@ public class FormatTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
index 83127dac2ff5..fac8ed9a3117 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
@@ -99,10 +99,7 @@ public class HasOnlyReadOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ListDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ListDto.java
index e33ef6f7310e..cd210a97fbf4 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ListDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ListDto.java
@@ -75,10 +75,7 @@ public class ListDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/MapTestDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/MapTestDto.java
index cf1017c5622a..0b9be76c2ec7 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/MapTestDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/MapTestDto.java
@@ -221,10 +221,7 @@ public class MapTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
index 82e6ef666d51..f43820540c2e 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
@@ -139,10 +139,7 @@ public class MixedPropertiesAndAdditionalPropertiesClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/Model200ResponseDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/Model200ResponseDto.java
index 072d411d4aa3..d56bf281170f 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/Model200ResponseDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/Model200ResponseDto.java
@@ -99,10 +99,7 @@ public class Model200ResponseDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/NameDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/NameDto.java
index effaa6af054f..9724bc4e5d9e 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/NameDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/NameDto.java
@@ -151,10 +151,7 @@ public class NameDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/NullableMapPropertyDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/NullableMapPropertyDto.java
index da5481da3c09..e19da72c6e06 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/NullableMapPropertyDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/NullableMapPropertyDto.java
@@ -99,10 +99,7 @@ public class NullableMapPropertyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/NumberOnlyDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/NumberOnlyDto.java
index 9a988f2dfab0..9aece07a21be 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/NumberOnlyDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/NumberOnlyDto.java
@@ -76,10 +76,7 @@ public class NumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/OrderDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/OrderDto.java
index a05427853216..f77864e09bb5 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/OrderDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/OrderDto.java
@@ -236,10 +236,7 @@ public class OrderDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/OuterCompositeDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/OuterCompositeDto.java
index c2fa61db983c..8d8379ad64d1 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/OuterCompositeDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/OuterCompositeDto.java
@@ -124,10 +124,7 @@ public class OuterCompositeDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ParentWithNullableDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ParentWithNullableDto.java
index 82c7233b9fa2..5cdfe0fcb9aa 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ParentWithNullableDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ParentWithNullableDto.java
@@ -157,10 +157,7 @@ public class ParentWithNullableDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/PetDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/PetDto.java
index 83b6345a4612..1a24ec243aa3 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/PetDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/PetDto.java
@@ -271,10 +271,7 @@ public class PetDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
index fc8c0a921622..6acc57d1eebd 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
@@ -99,10 +99,7 @@ public class ReadOnlyFirstDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java
index 5ec47f36a820..6b799da9dbd0 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java
@@ -147,10 +147,7 @@ public class ResponseObjectWithDifferentFieldNamesDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ReturnDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ReturnDto.java
index 906e0a6d8e5f..bfa3b297ed7f 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ReturnDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/ReturnDto.java
@@ -75,10 +75,7 @@ public class ReturnDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/SpecialModelNameDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/SpecialModelNameDto.java
index 620fea206a8e..799e62ec932b 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/SpecialModelNameDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/SpecialModelNameDto.java
@@ -75,10 +75,7 @@ public class SpecialModelNameDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/TagDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/TagDto.java
index b31518166c46..5b873d0f96f4 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/TagDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/TagDto.java
@@ -99,10 +99,7 @@ public class TagDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java
index e6a708b4aec3..a8f4e4e1fd51 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java
@@ -188,10 +188,7 @@ public class TypeHolderDefaultDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderExampleDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderExampleDto.java
index e95507b8ab6b..c32ef471e305 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderExampleDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderExampleDto.java
@@ -212,10 +212,7 @@ public class TypeHolderExampleDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/UserDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/UserDto.java
index 9cc5aea7f0b6..7779d89564ad 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/UserDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/UserDto.java
@@ -243,10 +243,7 @@ public class UserDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/XmlItemDto.java b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/XmlItemDto.java
index 1841ce750ffc..3ec5c601684a 100644
--- a/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/XmlItemDto.java
+++ b/samples/client/petstore/spring-http-interface-noResponseEntity/src/main/java/org/openapitools/model/XmlItemDto.java
@@ -832,10 +832,7 @@ public class XmlItemDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index cb6cae7d1ad6..7e91f16d54db 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -117,10 +117,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index b23ec88379cf..5bceba169811 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -118,10 +118,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index eb5ad102aeb9..7352896bfda4 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -117,10 +117,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index 5a3d64bd8b8d..79f0d803e95d 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -402,10 +402,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 4067a3ec21de..a75cbc653296 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -117,10 +117,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index d69b1b3a5ade..c53b1c7859e4 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -118,10 +118,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index 23a999e4a72c..b9966c0f410f 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -118,10 +118,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index 63f9dfacfaf3..5ac90441d825 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -117,10 +117,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Animal.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Animal.java
index 15184b01d3f8..565c92b87617 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Animal.java
@@ -122,10 +122,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ba61f9835179..18a388023448 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -86,10 +86,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index a3bc71272409..0950f897120e 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -86,10 +86,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayTest.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayTest.java
index cc6d426980da..a7ed1c8651d7 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayTest.java
@@ -152,10 +152,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/BigCat.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/BigCat.java
index fe01a05d34e1..6c8523bc81cf 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/BigCat.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/BigCat.java
@@ -146,10 +146,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Capitalization.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Capitalization.java
index 84f536df6f9f..d2d8d98e720d 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Capitalization.java
@@ -193,10 +193,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Cat.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Cat.java
index d54d60ba8ad8..a79c8ecc5516 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Cat.java
@@ -109,10 +109,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Category.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Category.java
index d08d6f9ea51b..9dfb4caa7b52 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Category.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Category.java
@@ -108,10 +108,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ChildWithNullable.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ChildWithNullable.java
index 44189d54ff3e..326c28e87672 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ChildWithNullable.java
@@ -104,10 +104,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ClassModel.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ClassModel.java
index 482bab1a95e7..501b93612a4c 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ClassModel.java
@@ -73,10 +73,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Client.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Client.java
index c702680c057d..9492dc94929a 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Client.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Client.java
@@ -73,10 +73,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ContainerDefaultValue.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ContainerDefaultValue.java
index 96c6c9266a15..49c05354cc12 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ContainerDefaultValue.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ContainerDefaultValue.java
@@ -207,10 +207,7 @@ public class ContainerDefaultValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Dog.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Dog.java
index 14b537cc870a..86870095d0f0 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Dog.java
@@ -101,10 +101,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumArrays.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumArrays.java
index cb834d6fd7a6..e3d6d1d01adb 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumArrays.java
@@ -180,10 +180,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumTest.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumTest.java
index 35f221720f99..6909c78712cb 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumTest.java
@@ -328,10 +328,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/File.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/File.java
index 058ddfd7d19c..5b774fefc30a 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/File.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/File.java
@@ -73,10 +73,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index f32f03314871..75c3385d02d5 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -110,10 +110,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/FormatTest.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/FormatTest.java
index e9cd0337c8b9..a6dd3413ee7d 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/FormatTest.java
@@ -419,10 +419,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index b9180ef4fde1..7dbcdddfa6aa 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -99,10 +99,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/MapTest.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/MapTest.java
index f5ed47f5b0f2..95d30de86bb9 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/MapTest.java
@@ -219,10 +219,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 23f814779210..6e681ebeddf3 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -137,10 +137,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Model200Response.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Model200Response.java
index 461f14970cfb..36169b151aa4 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Model200Response.java
@@ -99,10 +99,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelApiResponse.java
index 2ed2d38b40ab..f9aea2a7d56d 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -123,10 +123,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelList.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelList.java
index b692796f41b5..2e8b5ef481e6 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelList.java
@@ -75,10 +75,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelReturn.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelReturn.java
index 2b048f37800f..30f0b4da5688 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelReturn.java
@@ -75,10 +75,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Name.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Name.java
index ac352ddf52d6..5a2e4e45da41 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Name.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Name.java
@@ -156,10 +156,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/NullableMapProperty.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/NullableMapProperty.java
index ad1884911b49..0012f126580c 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/NullableMapProperty.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/NullableMapProperty.java
@@ -97,10 +97,7 @@ public class NullableMapProperty {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/NumberOnly.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/NumberOnly.java
index df0e337d3922..53098f5998c5 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/NumberOnly.java
@@ -74,10 +74,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Order.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Order.java
index c7f80609f489..c055b3741b06 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Order.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Order.java
@@ -234,10 +234,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/OuterComposite.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/OuterComposite.java
index 5a5d7433f4d1..c181df7b7a37 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/OuterComposite.java
@@ -122,10 +122,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ParentWithNullable.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ParentWithNullable.java
index e76c0b559382..e25d99b16c09 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ParentWithNullable.java
@@ -156,10 +156,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Pet.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Pet.java
index a028f088e770..a90496ee0ab1 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Pet.java
@@ -277,10 +277,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index 6473ee3056ea..e2d634c9b61c 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -97,10 +97,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
index 0f08f457ad03..e4816ae9d185 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
@@ -145,10 +145,7 @@ public class ResponseObjectWithDifferentFieldNames {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/SpecialModelName.java
index 24573f4ad3d7..b53f1e998ced 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -75,10 +75,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Tag.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Tag.java
index 9585008fca3f..60070f1058ac 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/Tag.java
@@ -97,10 +97,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderDefault.java
index b018ce0ade56..84f05c9549d2 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -197,10 +197,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderExample.java
index 1577547da27c..f6a571f7a059 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -222,10 +222,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/User.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/User.java
index 17a0cfe5170b..6804a2c4c7fd 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/User.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/User.java
@@ -241,10 +241,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/XmlItem.java b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/XmlItem.java
index e1cf69f08880..d48283aeff89 100644
--- a/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/client/petstore/spring-http-interface-reactive-noResponseEntity/src/main/java/org/openapitools/model/XmlItem.java
@@ -830,10 +830,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index cb6cae7d1ad6..7e91f16d54db 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -117,10 +117,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index b23ec88379cf..5bceba169811 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -118,10 +118,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index eb5ad102aeb9..7352896bfda4 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -117,10 +117,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index 5a3d64bd8b8d..79f0d803e95d 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -402,10 +402,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 4067a3ec21de..a75cbc653296 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -117,10 +117,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index d69b1b3a5ade..c53b1c7859e4 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -118,10 +118,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index 23a999e4a72c..b9966c0f410f 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -118,10 +118,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index 63f9dfacfaf3..5ac90441d825 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -117,10 +117,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Animal.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Animal.java
index 15184b01d3f8..565c92b87617 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Animal.java
@@ -122,10 +122,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ba61f9835179..18a388023448 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -86,10 +86,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index a3bc71272409..0950f897120e 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -86,10 +86,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayTest.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayTest.java
index cc6d426980da..a7ed1c8651d7 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayTest.java
@@ -152,10 +152,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/BigCat.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/BigCat.java
index fe01a05d34e1..6c8523bc81cf 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/BigCat.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/BigCat.java
@@ -146,10 +146,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Capitalization.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Capitalization.java
index 84f536df6f9f..d2d8d98e720d 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Capitalization.java
@@ -193,10 +193,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Cat.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Cat.java
index d54d60ba8ad8..a79c8ecc5516 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Cat.java
@@ -109,10 +109,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Category.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Category.java
index d08d6f9ea51b..9dfb4caa7b52 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Category.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Category.java
@@ -108,10 +108,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ChildWithNullable.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ChildWithNullable.java
index 44189d54ff3e..326c28e87672 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ChildWithNullable.java
@@ -104,10 +104,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ClassModel.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ClassModel.java
index 482bab1a95e7..501b93612a4c 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ClassModel.java
@@ -73,10 +73,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Client.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Client.java
index c702680c057d..9492dc94929a 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Client.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Client.java
@@ -73,10 +73,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ContainerDefaultValue.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ContainerDefaultValue.java
index 96c6c9266a15..49c05354cc12 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ContainerDefaultValue.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ContainerDefaultValue.java
@@ -207,10 +207,7 @@ public class ContainerDefaultValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Dog.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Dog.java
index 14b537cc870a..86870095d0f0 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Dog.java
@@ -101,10 +101,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/EnumArrays.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/EnumArrays.java
index cb834d6fd7a6..e3d6d1d01adb 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/EnumArrays.java
@@ -180,10 +180,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/EnumTest.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/EnumTest.java
index 35f221720f99..6909c78712cb 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/EnumTest.java
@@ -328,10 +328,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/File.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/File.java
index 058ddfd7d19c..5b774fefc30a 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/File.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/File.java
@@ -73,10 +73,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index f32f03314871..75c3385d02d5 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -110,10 +110,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/FormatTest.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/FormatTest.java
index e9cd0337c8b9..a6dd3413ee7d 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/FormatTest.java
@@ -419,10 +419,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index b9180ef4fde1..7dbcdddfa6aa 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -99,10 +99,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/MapTest.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/MapTest.java
index f5ed47f5b0f2..95d30de86bb9 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/MapTest.java
@@ -219,10 +219,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 23f814779210..6e681ebeddf3 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -137,10 +137,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Model200Response.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Model200Response.java
index 461f14970cfb..36169b151aa4 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Model200Response.java
@@ -99,10 +99,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ModelApiResponse.java
index 2ed2d38b40ab..f9aea2a7d56d 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -123,10 +123,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ModelList.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ModelList.java
index b692796f41b5..2e8b5ef481e6 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ModelList.java
@@ -75,10 +75,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ModelReturn.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ModelReturn.java
index 2b048f37800f..30f0b4da5688 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ModelReturn.java
@@ -75,10 +75,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Name.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Name.java
index ac352ddf52d6..5a2e4e45da41 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Name.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Name.java
@@ -156,10 +156,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/NullableMapProperty.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/NullableMapProperty.java
index ad1884911b49..0012f126580c 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/NullableMapProperty.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/NullableMapProperty.java
@@ -97,10 +97,7 @@ public class NullableMapProperty {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/NumberOnly.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/NumberOnly.java
index df0e337d3922..53098f5998c5 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/NumberOnly.java
@@ -74,10 +74,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Order.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Order.java
index c7f80609f489..c055b3741b06 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Order.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Order.java
@@ -234,10 +234,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/OuterComposite.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/OuterComposite.java
index 5a5d7433f4d1..c181df7b7a37 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/OuterComposite.java
@@ -122,10 +122,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ParentWithNullable.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ParentWithNullable.java
index e76c0b559382..e25d99b16c09 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ParentWithNullable.java
@@ -156,10 +156,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Pet.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Pet.java
index a028f088e770..a90496ee0ab1 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Pet.java
@@ -277,10 +277,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index 6473ee3056ea..e2d634c9b61c 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -97,10 +97,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
index 0f08f457ad03..e4816ae9d185 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
@@ -145,10 +145,7 @@ public class ResponseObjectWithDifferentFieldNames {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/SpecialModelName.java
index 24573f4ad3d7..b53f1e998ced 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -75,10 +75,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Tag.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Tag.java
index 9585008fca3f..60070f1058ac 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Tag.java
@@ -97,10 +97,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/TypeHolderDefault.java
index b018ce0ade56..84f05c9549d2 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -197,10 +197,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/TypeHolderExample.java
index 1577547da27c..f6a571f7a059 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -222,10 +222,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/User.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/User.java
index 17a0cfe5170b..6804a2c4c7fd 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/User.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/User.java
@@ -241,10 +241,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/XmlItem.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/XmlItem.java
index e1cf69f08880..d48283aeff89 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/XmlItem.java
@@ -830,10 +830,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java
index 65bafcfb04c8..c559ed4caa74 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java
@@ -118,10 +118,7 @@ public class AdditionalPropertiesAnyTypeDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java
index a6d0152666fc..fc99434acab5 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java
@@ -119,10 +119,7 @@ public class AdditionalPropertiesArrayDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java
index 5a878e822089..3f496145ff73 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java
@@ -118,10 +118,7 @@ public class AdditionalPropertiesBooleanDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
index d75a139b5962..59cb79eca667 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
@@ -390,10 +390,7 @@ public class AdditionalPropertiesClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java
index 8ad49a74a5b0..0482cf028a7c 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java
@@ -118,10 +118,7 @@ public class AdditionalPropertiesIntegerDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java
index b8206149d5c3..89f1fa28c6ad 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java
@@ -119,10 +119,7 @@ public class AdditionalPropertiesNumberDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java
index b1d6e84c9def..187c8fa5afe3 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java
@@ -119,10 +119,7 @@ public class AdditionalPropertiesObjectDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java
index ff17e846272f..8bf74154da08 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java
@@ -118,10 +118,7 @@ public class AdditionalPropertiesStringDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AnimalDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AnimalDto.java
index 5cc8bb4805a5..3fb3a3d9a33d 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AnimalDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/AnimalDto.java
@@ -115,10 +115,7 @@ public class AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ApiResponseDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ApiResponseDto.java
index a376682bed47..c55bac6dc22f 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ApiResponseDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ApiResponseDto.java
@@ -122,10 +122,7 @@ public class ApiResponseDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
index 5cc8dbe9cf2a..b2200269557f 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
@@ -87,10 +87,7 @@ public class ArrayOfArrayOfNumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
index 3a4a81d55622..aae7fc2e371c 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
@@ -87,10 +87,7 @@ public class ArrayOfNumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ArrayTestDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ArrayTestDto.java
index 20981e410db9..20fc796f00f7 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ArrayTestDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ArrayTestDto.java
@@ -153,10 +153,7 @@ public class ArrayTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/BigCatDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/BigCatDto.java
index cd9ca53c58d2..b142fe9e907c 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/BigCatDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/BigCatDto.java
@@ -140,10 +140,7 @@ public class BigCatDto extends CatDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/CapitalizationDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/CapitalizationDto.java
index 6543d7375265..95146dd963b7 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/CapitalizationDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/CapitalizationDto.java
@@ -194,10 +194,7 @@ public class CapitalizationDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/CatDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/CatDto.java
index 5fbadc73e2fa..b3a40809e8bb 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/CatDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/CatDto.java
@@ -102,10 +102,7 @@ public class CatDto extends AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/CategoryDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/CategoryDto.java
index 04a39ba9e163..d7b74f7eb2e2 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/CategoryDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/CategoryDto.java
@@ -102,10 +102,7 @@ public class CategoryDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ChildWithNullableDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ChildWithNullableDto.java
index b92e1c8672b3..2db99fe4fc3a 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ChildWithNullableDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ChildWithNullableDto.java
@@ -92,10 +92,7 @@ public class ChildWithNullableDto extends ParentWithNullableDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ClassModelDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ClassModelDto.java
index 953323c0681f..0214d0115d31 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ClassModelDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ClassModelDto.java
@@ -74,10 +74,7 @@ public class ClassModelDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ClientDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ClientDto.java
index 82169ee9a1e7..51f9c586b728 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ClientDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ClientDto.java
@@ -74,10 +74,7 @@ public class ClientDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java
index 1d4aa8e4ac0d..8d16a739fcd3 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java
@@ -189,10 +189,7 @@ public class ContainerDefaultValueDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/DogDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/DogDto.java
index 6277190f8e21..d967a2f4836f 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/DogDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/DogDto.java
@@ -95,10 +95,7 @@ public class DogDto extends AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/EnumArraysDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/EnumArraysDto.java
index cfd05938f462..9fb27c6d2d98 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/EnumArraysDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/EnumArraysDto.java
@@ -181,10 +181,7 @@ public class EnumArraysDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/EnumTestDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/EnumTestDto.java
index 7dbdb1f77ff1..36f6971bead3 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/EnumTestDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/EnumTestDto.java
@@ -320,10 +320,7 @@ public class EnumTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/FileDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/FileDto.java
index 171906a090a1..6156568204f0 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/FileDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/FileDto.java
@@ -74,10 +74,7 @@ public class FileDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
index 4c08ac5d9108..fd779ee0be7b 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
@@ -111,10 +111,7 @@ public class FileSchemaTestClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/FormatTestDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/FormatTestDto.java
index ce6447afff86..799a2483e5d9 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/FormatTestDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/FormatTestDto.java
@@ -408,10 +408,7 @@ public class FormatTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
index ac65cae3aa4d..67c61e820b2a 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
@@ -98,10 +98,7 @@ public class HasOnlyReadOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ListDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ListDto.java
index 9047d5a76630..59920e0e47e8 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ListDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ListDto.java
@@ -74,10 +74,7 @@ public class ListDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/MapTestDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/MapTestDto.java
index c1776f7a8626..a7f529b49cbb 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/MapTestDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/MapTestDto.java
@@ -220,10 +220,7 @@ public class MapTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
index 1620a60b5b19..b86807071e6f 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
@@ -138,10 +138,7 @@ public class MixedPropertiesAndAdditionalPropertiesClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/Model200ResponseDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/Model200ResponseDto.java
index 932dcc69ace7..cb125398160f 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/Model200ResponseDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/Model200ResponseDto.java
@@ -98,10 +98,7 @@ public class Model200ResponseDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/NameDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/NameDto.java
index 74d39ef2cdeb..3184c53a41e8 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/NameDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/NameDto.java
@@ -150,10 +150,7 @@ public class NameDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/NullableMapPropertyDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/NullableMapPropertyDto.java
index 5fd8f148a402..9849865b0dcb 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/NullableMapPropertyDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/NullableMapPropertyDto.java
@@ -85,10 +85,7 @@ public class NullableMapPropertyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/NumberOnlyDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/NumberOnlyDto.java
index 823842023e7c..60e0a87fa15e 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/NumberOnlyDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/NumberOnlyDto.java
@@ -75,10 +75,7 @@ public class NumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/OrderDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/OrderDto.java
index 4c8d760e4099..86b3e44a8b77 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/OrderDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/OrderDto.java
@@ -235,10 +235,7 @@ public class OrderDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/OuterCompositeDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/OuterCompositeDto.java
index 520afdaea402..212f9a0f43ab 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/OuterCompositeDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/OuterCompositeDto.java
@@ -123,10 +123,7 @@ public class OuterCompositeDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ParentWithNullableDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ParentWithNullableDto.java
index 6b486f93add0..d00a29aaad84 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ParentWithNullableDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ParentWithNullableDto.java
@@ -143,10 +143,7 @@ public class ParentWithNullableDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/PetDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/PetDto.java
index b4339b9a4c49..46576a0e0b99 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/PetDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/PetDto.java
@@ -270,10 +270,7 @@ public class PetDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
index 91a07aaf9aa7..e3d4a51b86c6 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
@@ -98,10 +98,7 @@ public class ReadOnlyFirstDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java
index 6513b72e5b1b..58a0322dfa8c 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java
@@ -146,10 +146,7 @@ public class ResponseObjectWithDifferentFieldNamesDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ReturnDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ReturnDto.java
index 0bad23022fc3..4d20e8847acf 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ReturnDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/ReturnDto.java
@@ -74,10 +74,7 @@ public class ReturnDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/SpecialModelNameDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/SpecialModelNameDto.java
index a6e3b0bab0b5..6797ca0cfcdb 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/SpecialModelNameDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/SpecialModelNameDto.java
@@ -74,10 +74,7 @@ public class SpecialModelNameDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/TagDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/TagDto.java
index 5c87784be251..e6540c67b3cc 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/TagDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/TagDto.java
@@ -98,10 +98,7 @@ public class TagDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java
index 02582d835ac0..6583dfae5d54 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java
@@ -187,10 +187,7 @@ public class TypeHolderDefaultDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/TypeHolderExampleDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/TypeHolderExampleDto.java
index 8e187c07c213..b53a873600e6 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/TypeHolderExampleDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/TypeHolderExampleDto.java
@@ -211,10 +211,7 @@ public class TypeHolderExampleDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/UserDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/UserDto.java
index 593aba24f74d..f62b212849bb 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/UserDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/UserDto.java
@@ -242,10 +242,7 @@ public class UserDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/XmlItemDto.java b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/XmlItemDto.java
index e58f3f368cd9..6c440e794383 100644
--- a/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/XmlItemDto.java
+++ b/samples/client/petstore/spring-http-interface-springboot-4/src/main/java/org/openapitools/model/XmlItemDto.java
@@ -831,10 +831,7 @@ public class XmlItemDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java
index 5937c453e782..2611d3478847 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java
@@ -119,10 +119,7 @@ public class AdditionalPropertiesAnyTypeDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java
index dc20cbc33cdc..730aaf70ddab 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesArrayDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java
index 91310ef26bbf..cad28f5c1ce5 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java
@@ -119,10 +119,7 @@ public class AdditionalPropertiesBooleanDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
index c7ed595a5f15..bd8116825e06 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
@@ -404,10 +404,7 @@ public class AdditionalPropertiesClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java
index 32e1bc6b62a0..080a7851ef71 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java
@@ -119,10 +119,7 @@ public class AdditionalPropertiesIntegerDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java
index f8e8b94e7818..85709bac7c15 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesNumberDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java
index a1d840719628..c18f89761ce3 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesObjectDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java
index eb8a7e29d379..aa6651892dd5 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java
@@ -119,10 +119,7 @@ public class AdditionalPropertiesStringDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AnimalDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AnimalDto.java
index 943f1720c72c..a7828db1f81f 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AnimalDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/AnimalDto.java
@@ -116,10 +116,7 @@ public class AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ApiResponseDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ApiResponseDto.java
index ef8534255191..923775dc1bdb 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ApiResponseDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ApiResponseDto.java
@@ -123,10 +123,7 @@ public class ApiResponseDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
index 6572d7c4e8a7..322c7d51d232 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
@@ -88,10 +88,7 @@ public class ArrayOfArrayOfNumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
index 84f58748abe4..e554dec5aeb6 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
@@ -88,10 +88,7 @@ public class ArrayOfNumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayTestDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayTestDto.java
index e3def2e1fee1..9c6ab174ff14 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayTestDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayTestDto.java
@@ -154,10 +154,7 @@ public class ArrayTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/BigCatDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/BigCatDto.java
index 2de6bd531601..4cd6531fb1e7 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/BigCatDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/BigCatDto.java
@@ -141,10 +141,7 @@ public class BigCatDto extends CatDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/CapitalizationDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/CapitalizationDto.java
index 2a903a38fb67..e96926a07cfc 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/CapitalizationDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/CapitalizationDto.java
@@ -195,10 +195,7 @@ public class CapitalizationDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/CatDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/CatDto.java
index be24b518bbe9..88fbb22d8dbc 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/CatDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/CatDto.java
@@ -103,10 +103,7 @@ public class CatDto extends AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/CategoryDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/CategoryDto.java
index 9c13015b88f3..78f9b53f3359 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/CategoryDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/CategoryDto.java
@@ -103,10 +103,7 @@ public class CategoryDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ChildWithNullableDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ChildWithNullableDto.java
index 06f87e68f756..5500608d7521 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ChildWithNullableDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ChildWithNullableDto.java
@@ -106,10 +106,7 @@ public class ChildWithNullableDto extends ParentWithNullableDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ClassModelDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ClassModelDto.java
index 3de34bbd21f1..28d87018088a 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ClassModelDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ClassModelDto.java
@@ -75,10 +75,7 @@ public class ClassModelDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ClientDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ClientDto.java
index d933a0917e9c..44007998434b 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ClientDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ClientDto.java
@@ -75,10 +75,7 @@ public class ClientDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java
index 7390b1716da2..5fb6cea84bae 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java
@@ -201,10 +201,7 @@ public class ContainerDefaultValueDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/DogDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/DogDto.java
index a907ccf2e4b8..a8b326626e91 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/DogDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/DogDto.java
@@ -96,10 +96,7 @@ public class DogDto extends AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/EnumArraysDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/EnumArraysDto.java
index e69a98c73299..6b6cc2ffb304 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/EnumArraysDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/EnumArraysDto.java
@@ -182,10 +182,7 @@ public class EnumArraysDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/EnumTestDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/EnumTestDto.java
index fb94f5ce13fb..b99a01c6d0aa 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/EnumTestDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/EnumTestDto.java
@@ -321,10 +321,7 @@ public class EnumTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/FileDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/FileDto.java
index b17eed66258b..741bd42b27b0 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/FileDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/FileDto.java
@@ -75,10 +75,7 @@ public class FileDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
index 28763bdeaffd..d6a0651a7953 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
@@ -112,10 +112,7 @@ public class FileSchemaTestClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/FormatTestDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/FormatTestDto.java
index 4d8206d4a198..9699dd2c4298 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/FormatTestDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/FormatTestDto.java
@@ -409,10 +409,7 @@ public class FormatTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
index 83127dac2ff5..fac8ed9a3117 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
@@ -99,10 +99,7 @@ public class HasOnlyReadOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ListDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ListDto.java
index e33ef6f7310e..cd210a97fbf4 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ListDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ListDto.java
@@ -75,10 +75,7 @@ public class ListDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/MapTestDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/MapTestDto.java
index cf1017c5622a..0b9be76c2ec7 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/MapTestDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/MapTestDto.java
@@ -221,10 +221,7 @@ public class MapTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
index 82e6ef666d51..f43820540c2e 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
@@ -139,10 +139,7 @@ public class MixedPropertiesAndAdditionalPropertiesClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/Model200ResponseDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/Model200ResponseDto.java
index 072d411d4aa3..d56bf281170f 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/Model200ResponseDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/Model200ResponseDto.java
@@ -99,10 +99,7 @@ public class Model200ResponseDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/NameDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/NameDto.java
index effaa6af054f..9724bc4e5d9e 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/NameDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/NameDto.java
@@ -151,10 +151,7 @@ public class NameDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/NullableMapPropertyDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/NullableMapPropertyDto.java
index da5481da3c09..e19da72c6e06 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/NullableMapPropertyDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/NullableMapPropertyDto.java
@@ -99,10 +99,7 @@ public class NullableMapPropertyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/NumberOnlyDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/NumberOnlyDto.java
index 9a988f2dfab0..9aece07a21be 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/NumberOnlyDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/NumberOnlyDto.java
@@ -76,10 +76,7 @@ public class NumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/OrderDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/OrderDto.java
index a05427853216..f77864e09bb5 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/OrderDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/OrderDto.java
@@ -236,10 +236,7 @@ public class OrderDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/OuterCompositeDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/OuterCompositeDto.java
index c2fa61db983c..8d8379ad64d1 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/OuterCompositeDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/OuterCompositeDto.java
@@ -124,10 +124,7 @@ public class OuterCompositeDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ParentWithNullableDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ParentWithNullableDto.java
index 82c7233b9fa2..5cdfe0fcb9aa 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ParentWithNullableDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ParentWithNullableDto.java
@@ -157,10 +157,7 @@ public class ParentWithNullableDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/PetDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/PetDto.java
index 83b6345a4612..1a24ec243aa3 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/PetDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/PetDto.java
@@ -271,10 +271,7 @@ public class PetDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
index fc8c0a921622..6acc57d1eebd 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
@@ -99,10 +99,7 @@ public class ReadOnlyFirstDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java
index 5ec47f36a820..6b799da9dbd0 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java
@@ -147,10 +147,7 @@ public class ResponseObjectWithDifferentFieldNamesDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ReturnDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ReturnDto.java
index 906e0a6d8e5f..bfa3b297ed7f 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ReturnDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ReturnDto.java
@@ -75,10 +75,7 @@ public class ReturnDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/SpecialModelNameDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/SpecialModelNameDto.java
index 620fea206a8e..799e62ec932b 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/SpecialModelNameDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/SpecialModelNameDto.java
@@ -75,10 +75,7 @@ public class SpecialModelNameDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/TagDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/TagDto.java
index b31518166c46..5b873d0f96f4 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/TagDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/TagDto.java
@@ -99,10 +99,7 @@ public class TagDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java
index e6a708b4aec3..a8f4e4e1fd51 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java
@@ -188,10 +188,7 @@ public class TypeHolderDefaultDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/TypeHolderExampleDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/TypeHolderExampleDto.java
index e95507b8ab6b..c32ef471e305 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/TypeHolderExampleDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/TypeHolderExampleDto.java
@@ -212,10 +212,7 @@ public class TypeHolderExampleDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/UserDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/UserDto.java
index 9cc5aea7f0b6..7779d89564ad 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/UserDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/UserDto.java
@@ -243,10 +243,7 @@ public class UserDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/XmlItemDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/XmlItemDto.java
index 1841ce750ffc..3ec5c601684a 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/XmlItemDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/XmlItemDto.java
@@ -832,10 +832,7 @@ public class XmlItemDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/extensions/x-auth-id-alias/java/jersey2-java8/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/openapi3/client/extensions/x-auth-id-alias/java/jersey2-java8/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 5e624da2c6bc..f31b10d920d8 100644
--- a/samples/openapi3/client/extensions/x-auth-id-alias/java/jersey2-java8/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/openapi3/client/extensions/x-auth-id-alias/java/jersey2-java8/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -107,10 +107,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 9ae9e4eb951d..5cc5d0392d9e 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -107,10 +107,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/ChildSchema.java b/samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/ChildSchema.java
index 9670e7a673f7..1cdb10a5fc5e 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/ChildSchema.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/ChildSchema.java
@@ -155,10 +155,7 @@ public class ChildSchema extends Parent {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/MySchemaNameCharacters.java b/samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/MySchemaNameCharacters.java
index 07620024a03a..3190c7f28ba9 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/MySchemaNameCharacters.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/MySchemaNameCharacters.java
@@ -156,10 +156,7 @@ public class MySchemaNameCharacters extends Parent {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/Parent.java b/samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/Parent.java
index 7d227d831187..a5193770d295 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/Parent.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/Parent.java
@@ -113,10 +113,7 @@ public class Parent {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 6dfe5e09369d..2ec312f551c9 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -107,10 +107,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Category.java b/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Category.java
index 558d4d93ded6..b67ab57aa328 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Category.java
@@ -137,10 +137,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index bf2537757a26..2464e3878cdf 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -171,10 +171,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Order.java b/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Order.java
index 90b7c68c0b86..7cf95165e023 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Order.java
@@ -307,10 +307,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Pet.java b/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Pet.java
index a566d2928dd3..6167fde9f7a2 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Pet.java
@@ -331,10 +331,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Tag.java b/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Tag.java
index 51c5f8936fb2..3928a533136c 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Tag.java
@@ -137,10 +137,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/User.java b/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/User.java
index 692bd2ee991e..3030d279c795 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/User.java
@@ -335,10 +335,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 6dfe5e09369d..2ec312f551c9 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -107,10 +107,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Category.java b/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Category.java
index 91db898d12da..8560e46b611c 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Category.java
@@ -136,10 +136,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index b538c92ff537..3da6d921e3b9 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -170,10 +170,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Order.java b/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Order.java
index c0226a768dc2..588691099ef5 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Order.java
@@ -306,10 +306,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Pet.java b/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Pet.java
index b05b1c9cce10..8bbd420a7a4a 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Pet.java
@@ -330,10 +330,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Tag.java b/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Tag.java
index fb002485a9e8..d8776387535d 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Tag.java
@@ -136,10 +136,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/User.java b/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/User.java
index 948ca9d0778c..d10af20bc4fa 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/User.java
@@ -334,10 +334,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
index 925c0becb002..4f695fdbd251 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java
@@ -107,10 +107,7 @@ public abstract class AbstractOpenApiSchema {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
     public boolean equals(Object o) {
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index 275d720eaa2c..4b12df68160b 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -368,10 +368,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
index 7cb3f258d271..e7e93c0fb9ae 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AllOfRefToDouble.java
@@ -95,10 +95,7 @@ public class AllOfRefToDouble {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
index a10b6fd73973..e99ef7a91d9f 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AllOfRefToFloat.java
@@ -95,10 +95,7 @@ public class AllOfRefToFloat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AllOfRefToLong.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
index db35e2903820..fb484859cfa4 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AllOfRefToLong.java
@@ -95,10 +95,7 @@ public class AllOfRefToLong {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Animal.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Animal.java
index b509433722af..4b4df6492e5f 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Animal.java
@@ -139,10 +139,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Apple.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Apple.java
index 7fd906131252..0b60db184130 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Apple.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Apple.java
@@ -127,10 +127,7 @@ public class Apple {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AppleReq.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AppleReq.java
index 2c5054feefb8..a9ed23968673 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AppleReq.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AppleReq.java
@@ -127,10 +127,7 @@ public class AppleReq {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 36db77d85b94..dab169af1ec8 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -106,10 +106,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index c2bb538440ce..6e34e7c3bdad 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -106,10 +106,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayTest.java
index f06ee632e2ee..17e40a0f6212 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -184,10 +184,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Banana.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Banana.java
index f8644e2eace6..5cd191ce5064 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Banana.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Banana.java
@@ -97,10 +97,7 @@ public class Banana {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/BananaReq.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/BananaReq.java
index 6a39087f5da6..f8cd79947ace 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/BananaReq.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/BananaReq.java
@@ -128,10 +128,7 @@ public class BananaReq {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/BasquePig.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/BasquePig.java
index 7fea4daea5d0..89af10ce3946 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/BasquePig.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/BasquePig.java
@@ -95,10 +95,7 @@ public class BasquePig {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Capitalization.java
index 063999177dc4..02ffedf9df9f 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -250,10 +250,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Cat.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Cat.java
index f4d291d38995..d9e48d65cf1e 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Cat.java
@@ -149,10 +149,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Category.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Category.java
index ca880dc2b2ae..4a6acda7bb26 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Category.java
@@ -126,10 +126,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ChildCat.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ChildCat.java
index 2832454b5e09..6a04cd82138e 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ChildCat.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ChildCat.java
@@ -193,10 +193,7 @@ public class ChildCat extends ParentPet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ClassModel.java
index 42a76e612aaf..7af770c0144f 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -95,10 +95,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Client.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Client.java
index 0bacc1718546..7d9821904778 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Client.java
@@ -95,10 +95,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
index b594f4e6edf4..51348103a67c 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java
@@ -168,10 +168,7 @@ public class ComplexQuadrilateral {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/DanishPig.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/DanishPig.java
index b5390fedc2b1..1698648ac6c4 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/DanishPig.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/DanishPig.java
@@ -95,10 +95,7 @@ public class DanishPig {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/DeprecatedObject.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/DeprecatedObject.java
index 108075db4532..78e173526d47 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/DeprecatedObject.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/DeprecatedObject.java
@@ -97,10 +97,7 @@ public class DeprecatedObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Dog.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Dog.java
index 65d20a355589..b67b701d5c90 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Dog.java
@@ -148,10 +148,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Drawing.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Drawing.java
index 77367c6019f0..a75b1a6e6191 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Drawing.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Drawing.java
@@ -273,10 +273,7 @@ public class Drawing {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumArrays.java
index 57684e6c011e..436ae778c144 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -206,10 +206,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumTest.java
index 15364de1f871..b5903317c66a 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -549,10 +549,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EquilateralTriangle.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
index b94716827cb4..a730aad97cc6 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EquilateralTriangle.java
@@ -168,10 +168,7 @@ public class EquilateralTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 12b9b259fdfe..116ddea2cb09 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -137,10 +137,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Foo.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Foo.java
index 2e62ebac63fa..4c155083a3b5 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Foo.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Foo.java
@@ -95,10 +95,7 @@ public class Foo {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
index 446345bf0566..7e32e4bd9fd7 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java
@@ -97,10 +97,7 @@ public class FooGetDefaultResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FormatTest.java
index 14848a66a201..92a4bba50728 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -576,10 +576,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/GrandparentAnimal.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
index c41088f7b8f1..7e055064bce4 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/GrandparentAnimal.java
@@ -108,10 +108,7 @@ public class GrandparentAnimal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index a81195879717..8fa2906d4b6c 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -117,10 +117,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/HealthCheckResult.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/HealthCheckResult.java
index 5c9c9398455e..878d67739617 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/HealthCheckResult.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/HealthCheckResult.java
@@ -117,10 +117,7 @@ public class HealthCheckResult {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
index 6c5b6d16a9ec..5f7751c00d8b 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java
@@ -126,10 +126,7 @@ public class IsoscelesTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/MapTest.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/MapTest.java
index a10884f6edc2..aa34d5da6753 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/MapTest.java
@@ -257,10 +257,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 3ed285fafacc..5912de2edf61 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -170,10 +170,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Model200Response.java
index 7c65df7af747..5ee9ec6b5728 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -127,10 +127,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index 3e37d710b7c3..bc7b57ccd8ad 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -158,10 +158,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelFile.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelFile.java
index 91b874648065..b262e853dcc0 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelFile.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelFile.java
@@ -96,10 +96,7 @@ public class ModelFile {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelList.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelList.java
index aef8fb083c8c..7f12bf5d7d3b 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelList.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelList.java
@@ -96,10 +96,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelReturn.java
index 847d2d59dca8..b4340e499506 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -96,10 +96,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Name.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Name.java
index c69639ada399..f74cf4386ee1 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Name.java
@@ -178,10 +178,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NullableClass.java
index 2ac2cb29c782..c3f05fd09c99 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -634,10 +634,7 @@ public class NullableClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NumberOnly.java
index 344795376379..93a8d291b271 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -96,10 +96,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 7e3ffb80d903..33145a7de645 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -215,10 +215,7 @@ public class ObjectWithDeprecatedFields {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Order.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Order.java
index 6039280c7d69..c1ef90720c14 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Order.java
@@ -288,10 +288,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/OuterComposite.java
index 48a885c61328..7b5504a511a6 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -158,10 +158,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ParentPet.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ParentPet.java
index b53a681e3f0b..2d6b706dd861 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ParentPet.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ParentPet.java
@@ -120,10 +120,7 @@ public class ParentPet extends GrandparentAnimal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
   static {
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Pet.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Pet.java
index 6b7aa036fb1a..0e5b319c1133 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Pet.java
@@ -307,10 +307,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
index 1bd36a636925..8c22c9660b50 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java
@@ -95,10 +95,7 @@ public class QuadrilateralInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index 3d87c49842ff..db39df0a4a44 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -124,10 +124,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ScaleneTriangle.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
index 47f3cc3615e1..79017f332d26 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ScaleneTriangle.java
@@ -168,10 +168,7 @@ public class ScaleneTriangle {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ShapeInterface.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ShapeInterface.java
index 0d36947c8a32..bff19af8edfb 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ShapeInterface.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ShapeInterface.java
@@ -95,10 +95,7 @@ public class ShapeInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
index 77bda5b1713e..aeabf68a7d7c 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java
@@ -168,10 +168,7 @@ public class SimpleQuadrilateral {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/SpecialModelName.java
index e2dc371ea493..917994ca5532 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -127,10 +127,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Tag.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Tag.java
index 311c2fa1abd9..f42a877fefde 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Tag.java
@@ -126,10 +126,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
index dba5edb57ccd..bde86ac5781d 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -138,10 +138,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/TriangleInterface.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/TriangleInterface.java
index 7357f43e161a..d73947ab973c 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/TriangleInterface.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/TriangleInterface.java
@@ -95,10 +95,7 @@ public class TriangleInterface {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/User.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/User.java
index d4618f83464d..2c0c9f7875d7 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/User.java
@@ -472,10 +472,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Whale.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Whale.java
index e1597ae9b15e..a006a3c3dc67 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Whale.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Whale.java
@@ -158,10 +158,7 @@ public class Whale {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Zebra.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Zebra.java
index e0d4343a607b..ab031adc8677 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Zebra.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Zebra.java
@@ -206,10 +206,7 @@ public class Zebra {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 }
diff --git a/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Category.java
index 824937094806..5c82421a8c5b 100644
--- a/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Category.java
@@ -98,10 +98,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/ModelApiResponse.java
index 850dc4763ab5..b382c9d9a76a 100644
--- a/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -124,10 +124,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Order.java
index 19bd81e1b682..76131d6e61a1 100644
--- a/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Order.java
@@ -235,10 +235,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Pet.java
index ad6422063250..f71de7e9dba7 100644
--- a/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Pet.java
@@ -274,10 +274,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Tag.java
index 4d6136aa01d3..50655566375d 100644
--- a/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Tag.java
@@ -98,10 +98,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/User.java b/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/User.java
index 7669232a3504..f88d08025d27 100644
--- a/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/User.java
@@ -242,10 +242,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Category.java
index 357f641c5342..2644292a635e 100644
--- a/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Category.java
@@ -102,10 +102,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/ModelApiResponse.java
index b055d2a6c0c0..f841e45f0348 100644
--- a/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Order.java
index 0edad61a16d1..bfff46380e8d 100644
--- a/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Pet.java
index 4b2128266585..4561fa62380a 100644
--- a/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Pet.java
@@ -282,10 +282,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Tag.java
index 819f9a34d908..c9272229fa3c 100644
--- a/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/User.java b/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/User.java
index b0d85aea44e6..96e8b8ecb311 100644
--- a/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/Category.java
index 759b8be36d3c..c745379ec863 100644
--- a/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/Category.java
@@ -97,10 +97,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/ModelApiResponse.java
index 360cce17adac..a7cc7a8c076a 100644
--- a/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -123,10 +123,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/Order.java
index 9e5a85befc93..30c0a01327e0 100644
--- a/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/Order.java
@@ -234,10 +234,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/Pet.java
index 5a7135596642..ea1025927377 100644
--- a/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/Pet.java
@@ -273,10 +273,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/Tag.java
index 8bb1992fd056..4411b2f6db3b 100644
--- a/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/Tag.java
@@ -97,10 +97,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/User.java b/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/User.java
index 99189278a891..940517699a34 100644
--- a/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/client/petstore/spring-cloud-4-with-optional/src/main/java/org/openapitools/model/User.java
@@ -241,10 +241,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Category.java
index a83df46e1b37..24b392308f53 100644
--- a/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Category.java
@@ -102,10 +102,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/ModelApiResponse.java
index fd3c591671e8..edeb1f66019e 100644
--- a/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Order.java
index 47c00ea1a56a..0c245c5f9f2c 100644
--- a/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Pet.java
index 0ed1300e039b..06067f7a0c84 100644
--- a/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Pet.java
@@ -282,10 +282,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Tag.java
index f8a38e352878..1f94a8ef63aa 100644
--- a/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/User.java b/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/User.java
index 4e55c123cbf5..ae9bf7482766 100644
--- a/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-date-time/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-cloud-date-time/src/main/java/org/openapitools/model/Pet.java
index 7c350411e88e..2d058be64a67 100644
--- a/samples/openapi3/client/petstore/spring-cloud-date-time/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-cloud-date-time/src/main/java/org/openapitools/model/Pet.java
@@ -218,10 +218,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-http-basic/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/client/petstore/spring-cloud-http-basic/src/main/java/org/openapitools/model/Category.java
index a83df46e1b37..24b392308f53 100644
--- a/samples/openapi3/client/petstore/spring-cloud-http-basic/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/client/petstore/spring-cloud-http-basic/src/main/java/org/openapitools/model/Category.java
@@ -102,10 +102,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-http-basic/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-cloud-http-basic/src/main/java/org/openapitools/model/Pet.java
index 0ed1300e039b..06067f7a0c84 100644
--- a/samples/openapi3/client/petstore/spring-cloud-http-basic/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-cloud-http-basic/src/main/java/org/openapitools/model/Pet.java
@@ -282,10 +282,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-http-basic/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/client/petstore/spring-cloud-http-basic/src/main/java/org/openapitools/model/Tag.java
index f8a38e352878..1f94a8ef63aa 100644
--- a/samples/openapi3/client/petstore/spring-cloud-http-basic/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/client/petstore/spring-cloud-http-basic/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index 9bed3605a83a..df23b2e0518f 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index f99436d96a05..6455b1d28477 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index a0bd52301143..cf9ce0f5e925 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index a6be2fb360ac..3d7389bec4c9 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -415,10 +415,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index ce5fca38d97e..3bdc569be02e 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index 75b6411f9486..0848aa710a2e 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index 2f79b622e77d..129dd92b5337 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index a398997f37f3..143e46a8644e 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Animal.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Animal.java
index ee5823dc0798..885da6e05476 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Animal.java
@@ -119,10 +119,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index f03af73fd905..eeae40cafa74 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -89,10 +89,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 47cfb85cee87..1b5d034f4ac8 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -89,10 +89,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayTest.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayTest.java
index 994e26756e0e..5951b8f4f981 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayTest.java
@@ -157,10 +157,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/BigCat.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/BigCat.java
index 1b983c02abc0..06a6dc29220d 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/BigCat.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/BigCat.java
@@ -142,10 +142,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Capitalization.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Capitalization.java
index 65e6a969342c..afedf33fe0ba 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Capitalization.java
@@ -201,10 +201,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Cat.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Cat.java
index efb954279cf8..626d7ef8c1d7 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Cat.java
@@ -105,10 +105,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Category.java
index 16da4b569928..cdfed478a9b0 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Category.java
@@ -105,10 +105,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ChildWithNullable.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ChildWithNullable.java
index 3378761ed1e9..01cc7eb0462e 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ChildWithNullable.java
@@ -107,10 +107,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ClassModel.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ClassModel.java
index 9f97de621a29..3b17108cd459 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ClassModel.java
@@ -77,10 +77,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Client.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Client.java
index ad6d1b9c0d99..7f3a323e6af1 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Client.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Client.java
@@ -76,10 +76,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ContainerDefaultValue.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ContainerDefaultValue.java
index bec564f0d907..b309bf6cdae5 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ContainerDefaultValue.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ContainerDefaultValue.java
@@ -205,10 +205,7 @@ public class ContainerDefaultValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Dog.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Dog.java
index 1a8150e182ad..ad240b14e8cd 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Dog.java
@@ -97,10 +97,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/EnumArrays.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/EnumArrays.java
index 6879efae982d..1c6836270e59 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/EnumArrays.java
@@ -184,10 +184,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/EnumTest.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/EnumTest.java
index dbeaa57e3d59..62d3a1204dc9 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/EnumTest.java
@@ -328,10 +328,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/File.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/File.java
index 70b59bd54553..3c808c2564fd 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/File.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/File.java
@@ -77,10 +77,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index 2e4d091a2030..b1da5f0f051d 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -114,10 +114,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/FormatTest.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/FormatTest.java
index b4a589971adc..6069892670be 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/FormatTest.java
@@ -425,10 +425,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 7f88fb964a28..9e99407cc172 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -103,10 +103,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/MapTest.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/MapTest.java
index 1f4517b1d4d0..0df5143e02ae 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/MapTest.java
@@ -225,10 +225,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 1e69f24f03c5..a2b9f47bf9ca 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -142,10 +142,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Model200Response.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Model200Response.java
index ff1f86102e2e..c750a0d6534e 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Model200Response.java
@@ -104,10 +104,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ModelApiResponse.java
index 435055a10a58..f4bc1158e557 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -128,10 +128,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ModelList.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ModelList.java
index 34f55886cc98..60a860c7e5a6 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ModelList.java
@@ -78,10 +78,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ModelReturn.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ModelReturn.java
index 50ef51c9cbf5..e1062706a03f 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ModelReturn.java
@@ -79,10 +79,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Name.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Name.java
index 837e001de034..0903e5325ebf 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Name.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Name.java
@@ -156,10 +156,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/NullableMapProperty.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/NullableMapProperty.java
index 7f51e3098f2a..c7d431471e4d 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/NullableMapProperty.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/NullableMapProperty.java
@@ -100,10 +100,7 @@ public class NullableMapProperty {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/NumberOnly.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/NumberOnly.java
index ada5eb7bc169..24f388d18059 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/NumberOnly.java
@@ -77,10 +77,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Order.java
index d556a66ac5fc..a8a085046bed 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Order.java
@@ -242,10 +242,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/OuterComposite.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/OuterComposite.java
index 0a9dd63af928..f33e0a655695 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/OuterComposite.java
@@ -127,10 +127,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ParentWithNullable.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ParentWithNullable.java
index b49d7563a96e..7c079520417f 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ParentWithNullable.java
@@ -160,10 +160,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Pet.java
index 5da7ff0226dc..690f46430f12 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Pet.java
@@ -277,10 +277,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index 31d7faf6874e..8ca5a82f9c01 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -101,10 +101,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
index ac5973a769b5..064c39c2d87e 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
@@ -151,10 +151,7 @@ public class ResponseObjectWithDifferentFieldNames {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/SpecialModelName.java
index 0e98f6caaae8..d4ab4718139c 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -78,10 +78,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Tag.java
index 10e80a133066..ece3f449fa18 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Tag.java
@@ -101,10 +101,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 7748127766a5..173ef598d332 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -193,10 +193,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/TypeHolderExample.java
index 7c7502e00715..5cd52b78c6b8 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -218,10 +218,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/User.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/User.java
index eabdbbb318cc..1e26e2d0fc35 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/User.java
@@ -251,10 +251,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/XmlItem.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/XmlItem.java
index 4fa5151512af..bb65cd50c02f 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/XmlItem.java
@@ -861,10 +861,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Category.java
index da5fb78e703d..ab58c7833530 100644
--- a/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Category.java
@@ -102,10 +102,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/ModelApiResponse.java
index fd3c591671e8..edeb1f66019e 100644
--- a/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Order.java
index 47c00ea1a56a..0c245c5f9f2c 100644
--- a/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Pet.java
index 8140d0f63a9d..f28d8ab37276 100644
--- a/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Pet.java
@@ -275,10 +275,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Tag.java
index f8a38e352878..1f94a8ef63aa 100644
--- a/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/User.java b/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/User.java
index 4e55c123cbf5..ae9bf7482766 100644
--- a/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Category.java
index a83df46e1b37..24b392308f53 100644
--- a/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Category.java
@@ -102,10 +102,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/ModelApiResponse.java
index fd3c591671e8..edeb1f66019e 100644
--- a/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Order.java
index 47c00ea1a56a..0c245c5f9f2c 100644
--- a/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Pet.java
index 0ed1300e039b..06067f7a0c84 100644
--- a/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Pet.java
@@ -282,10 +282,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Tag.java
index f8a38e352878..1f94a8ef63aa 100644
--- a/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/User.java b/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/User.java
index 4e55c123cbf5..ae9bf7482766 100644
--- a/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Category.java
index a83df46e1b37..24b392308f53 100644
--- a/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Category.java
@@ -102,10 +102,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/ModelApiResponse.java
index fd3c591671e8..edeb1f66019e 100644
--- a/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Order.java
index 47c00ea1a56a..0c245c5f9f2c 100644
--- a/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Pet.java
index 0ed1300e039b..06067f7a0c84 100644
--- a/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Pet.java
@@ -282,10 +282,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Tag.java
index f8a38e352878..1f94a8ef63aa 100644
--- a/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/User.java b/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/User.java
index 4e55c123cbf5..ae9bf7482766 100644
--- a/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Category.java
index a83df46e1b37..24b392308f53 100644
--- a/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Category.java
@@ -102,10 +102,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/ModelApiResponse.java
index fd3c591671e8..edeb1f66019e 100644
--- a/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Order.java
index 47c00ea1a56a..0c245c5f9f2c 100644
--- a/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Pet.java
index 0ed1300e039b..06067f7a0c84 100644
--- a/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Pet.java
@@ -282,10 +282,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Tag.java
index f8a38e352878..1f94a8ef63aa 100644
--- a/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/User.java b/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/User.java
index 4e55c123cbf5..ae9bf7482766 100644
--- a/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Addressable.java b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Addressable.java
index 11c7a18732e3..d8162b3f91a2 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Addressable.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Addressable.java
@@ -102,10 +102,7 @@ public class Addressable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Apple.java b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Apple.java
index 12cd9a178855..e381059d67af 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Apple.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Apple.java
@@ -117,10 +117,7 @@ public class Apple implements Fruit {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Banana.java b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Banana.java
index 68cc915dc7ed..06fef9ffcff4 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Banana.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Banana.java
@@ -117,10 +117,7 @@ public class Banana implements Fruit {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Bar.java b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Bar.java
index a15673579b86..86c573ca7c25 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Bar.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Bar.java
@@ -191,10 +191,7 @@ public class Bar extends Entity implements BarRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/BarCreate.java b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/BarCreate.java
index da7124c77f74..400b46e9ce48 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/BarCreate.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/BarCreate.java
@@ -172,10 +172,7 @@ public class BarCreate extends Entity {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/BarRef.java b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/BarRef.java
index d5f50d0ef8fc..8802dae74372 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/BarRef.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/BarRef.java
@@ -103,10 +103,7 @@ public class BarRef extends EntityRef implements BarRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Cat.java b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Cat.java
index bb2064becf93..1db6e911bdb0 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Cat.java
@@ -76,10 +76,7 @@ public class Cat implements Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Dog.java b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Dog.java
index a14c95296b3d..bb0d3ac902eb 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Dog.java
@@ -76,10 +76,7 @@ public class Dog implements Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Entity.java b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Entity.java
index 8ee421549dd0..af73ae0e4c02 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Entity.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Entity.java
@@ -204,10 +204,7 @@ public class Entity {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/EntityRef.java b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/EntityRef.java
index 85e8dc5d06dc..98766ff08319 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/EntityRef.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/EntityRef.java
@@ -250,10 +250,7 @@ public class EntityRef {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Extensible.java b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Extensible.java
index 058a317ff626..76bf0a596ead 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Extensible.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Extensible.java
@@ -137,10 +137,7 @@ public class Extensible {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Foo.java b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Foo.java
index 06d1b5dccdd4..f86fefddf063 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Foo.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Foo.java
@@ -144,10 +144,7 @@ public class Foo extends Entity implements FooRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/FooRef.java b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/FooRef.java
index 9785308f23b6..d1cec77b4571 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/FooRef.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/FooRef.java
@@ -129,10 +129,7 @@ public class FooRef extends EntityRef implements FooRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Pasta.java b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Pasta.java
index e3ff8de1f78e..74871b6697cd 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Pasta.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Pasta.java
@@ -119,10 +119,7 @@ public class Pasta extends Entity {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Pizza.java b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Pizza.java
index 5fa2d353a96d..bab5f198d092 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Pizza.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/Pizza.java
@@ -128,10 +128,7 @@ public class Pizza extends Entity {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/PizzaSpeziale.java b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/PizzaSpeziale.java
index 71a0b0878b21..47cc8773f0ea 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/PizzaSpeziale.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-interface/src/main/java/org/openapitools/model/PizzaSpeziale.java
@@ -125,10 +125,7 @@ public class PizzaSpeziale extends Pizza {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Addressable.java b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Addressable.java
index 131b3c7c3152..5042c77e19ac 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Addressable.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Addressable.java
@@ -102,10 +102,7 @@ public final class Addressable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Apple.java b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Apple.java
index 8559c4d5ce5f..df20b31c5523 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Apple.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Apple.java
@@ -117,10 +117,7 @@ public final class Apple implements Fruit {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Banana.java b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Banana.java
index 0ea65c5efce1..47c688ea9c78 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Banana.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Banana.java
@@ -117,10 +117,7 @@ public final class Banana implements Fruit {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Bar.java b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Bar.java
index 2c4859b461b9..4fd0682f01e7 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Bar.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Bar.java
@@ -191,10 +191,7 @@ public final class Bar extends Entity implements BarRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends Entity.Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/BarCreate.java b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/BarCreate.java
index 91798e9fd66d..38fbebfbec0a 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/BarCreate.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/BarCreate.java
@@ -172,10 +172,7 @@ public final class BarCreate extends Entity {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends Entity.Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/BarRef.java b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/BarRef.java
index abec7f5a2363..cb27398fc353 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/BarRef.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/BarRef.java
@@ -103,10 +103,7 @@ public final class BarRef extends EntityRef implements BarRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends EntityRef.Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Cat.java b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Cat.java
index 076eb54d60b3..5399bb08e217 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Cat.java
@@ -76,10 +76,7 @@ public final class Cat implements Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Dog.java b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Dog.java
index c4d809f4efc1..cc95b0dacb16 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Dog.java
@@ -76,10 +76,7 @@ public final class Dog implements Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Entity.java b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Entity.java
index f755232091e2..7db66ecbb624 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Entity.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Entity.java
@@ -204,10 +204,7 @@ public sealed class Entity permits Bar, BarCreate, Foo, Pasta, Pizza {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/EntityRef.java b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/EntityRef.java
index f9308f2c0c6c..465096e55e8a 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/EntityRef.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/EntityRef.java
@@ -250,10 +250,7 @@ public sealed class EntityRef permits BarRef, FooRef {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Extensible.java b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Extensible.java
index 57b8e5481ab3..2ff2107ade50 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Extensible.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Extensible.java
@@ -137,10 +137,7 @@ public final class Extensible {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Foo.java b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Foo.java
index ad878777e1c9..4be3403a3eba 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Foo.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Foo.java
@@ -144,10 +144,7 @@ public final class Foo extends Entity implements FooRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends Entity.Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/FooRef.java b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/FooRef.java
index 14e94173e7b9..886119a0d3d8 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/FooRef.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/FooRef.java
@@ -129,10 +129,7 @@ public final class FooRef extends EntityRef implements FooRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends EntityRef.Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Pasta.java b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Pasta.java
index cbb1d1192557..b2eab251dd1d 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Pasta.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Pasta.java
@@ -119,10 +119,7 @@ public final class Pasta extends Entity {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends Entity.Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Pizza.java b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Pizza.java
index 59fffff0d92e..4e6cbc3142c8 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Pizza.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/Pizza.java
@@ -128,10 +128,7 @@ public sealed class Pizza extends Entity permits PizzaSpeziale {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends Entity.Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/PizzaSpeziale.java b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/PizzaSpeziale.java
index e73f547e41b3..6d976aedfde2 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/PizzaSpeziale.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof-sealed/src/main/java/org/openapitools/model/PizzaSpeziale.java
@@ -125,10 +125,7 @@ public final class PizzaSpeziale extends Pizza {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends Pizza.Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Addressable.java b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Addressable.java
index 582d5f2489de..7d6ebf03bfa5 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Addressable.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Addressable.java
@@ -102,10 +102,7 @@ public class Addressable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Apple.java b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Apple.java
index 2ecda8022ebe..1d1b1066713a 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Apple.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Apple.java
@@ -117,10 +117,7 @@ public class Apple implements Fruit {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Banana.java b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Banana.java
index 606039dc9b9e..49140d728285 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Banana.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Banana.java
@@ -117,10 +117,7 @@ public class Banana implements Fruit {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Bar.java b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Bar.java
index c4b398648891..9b786617361e 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Bar.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Bar.java
@@ -191,10 +191,7 @@ public class Bar extends Entity implements BarRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends Entity.Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/BarCreate.java b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/BarCreate.java
index 7cacde74ddf4..08f599a565f5 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/BarCreate.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/BarCreate.java
@@ -172,10 +172,7 @@ public class BarCreate extends Entity {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends Entity.Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/BarRef.java b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/BarRef.java
index c292ad5c4b0a..8bf8036199ea 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/BarRef.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/BarRef.java
@@ -103,10 +103,7 @@ public class BarRef extends EntityRef implements BarRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends EntityRef.Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Cat.java b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Cat.java
index a4aa59761243..0c4ad178a909 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Cat.java
@@ -76,10 +76,7 @@ public class Cat implements Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Dog.java b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Dog.java
index 0ab6f6f751f0..8af26d59355a 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Dog.java
@@ -76,10 +76,7 @@ public class Dog implements Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Entity.java b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Entity.java
index 95550164a578..d6d718373d48 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Entity.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Entity.java
@@ -204,10 +204,7 @@ public class Entity {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/EntityRef.java b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/EntityRef.java
index ac0bd18549b2..1b2f21f2b74a 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/EntityRef.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/EntityRef.java
@@ -250,10 +250,7 @@ public class EntityRef {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Extensible.java b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Extensible.java
index 2510bfc84b4f..803d7514c1cf 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Extensible.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Extensible.java
@@ -137,10 +137,7 @@ public class Extensible {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Foo.java b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Foo.java
index 082cbd1d15ad..57da44963eb1 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Foo.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Foo.java
@@ -144,10 +144,7 @@ public class Foo extends Entity implements FooRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends Entity.Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/FooRef.java b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/FooRef.java
index 0734980b34db..15ef4ce2910a 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/FooRef.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/FooRef.java
@@ -129,10 +129,7 @@ public class FooRef extends EntityRef implements FooRefOrValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends EntityRef.Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Pasta.java b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Pasta.java
index 59cf837c8767..4e1a0c0badfd 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Pasta.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Pasta.java
@@ -119,10 +119,7 @@ public class Pasta extends Entity {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends Entity.Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Pizza.java b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Pizza.java
index 962bdf9fd099..0714478e63a2 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Pizza.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/Pizza.java
@@ -128,10 +128,7 @@ public class Pizza extends Entity {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends Entity.Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/PizzaSpeziale.java b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/PizzaSpeziale.java
index 67dcc706d94d..2d74afb89cdf 100644
--- a/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/PizzaSpeziale.java
+++ b/samples/openapi3/server/petstore/spring-boot-oneof/src/main/java/org/openapitools/model/PizzaSpeziale.java
@@ -125,10 +125,7 @@ public class PizzaSpeziale extends Pizza {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends Pizza.Builder {
diff --git a/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Category.java
index a83df46e1b37..24b392308f53 100644
--- a/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Category.java
@@ -102,10 +102,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/ModelApiResponse.java
index fd3c591671e8..edeb1f66019e 100644
--- a/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Order.java
index 47c00ea1a56a..0c245c5f9f2c 100644
--- a/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Pet.java
index 0ed1300e039b..06067f7a0c84 100644
--- a/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Pet.java
@@ -282,10 +282,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Tag.java
index f8a38e352878..1f94a8ef63aa 100644
--- a/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/User.java b/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/User.java
index 4e55c123cbf5..ae9bf7482766 100644
--- a/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/Category.java
index e030bae999bf..0c187490d1be 100644
--- a/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/Category.java
@@ -127,10 +127,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/ModelApiResponse.java
index 58505ffc328c..4007838bc450 100644
--- a/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -158,10 +158,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/Order.java
index cedaf1014f67..79b1cd3f3065 100644
--- a/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/Order.java
@@ -284,10 +284,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/Pet.java
index 835712e30cc8..cf499b2a97bd 100644
--- a/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/Pet.java
@@ -325,10 +325,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/Tag.java
index 942d681e5be4..75bb4083bbd1 100644
--- a/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/Tag.java
@@ -127,10 +127,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/User.java b/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/User.java
index 28493cf7ae25..24a8bf9ab84b 100644
--- a/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/server/petstore/springboot-3-include-http-request-context/src/main/java/org/openapitools/model/User.java
@@ -301,10 +301,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Category.java
index e030bae999bf..0c187490d1be 100644
--- a/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Category.java
@@ -127,10 +127,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/ModelApiResponse.java
index 58505ffc328c..4007838bc450 100644
--- a/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -158,10 +158,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Order.java
index cedaf1014f67..79b1cd3f3065 100644
--- a/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Order.java
@@ -284,10 +284,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Pet.java
index 835712e30cc8..cf499b2a97bd 100644
--- a/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Pet.java
@@ -325,10 +325,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Tag.java
index 942d681e5be4..75bb4083bbd1 100644
--- a/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Tag.java
@@ -127,10 +127,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/User.java b/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/User.java
index 28493cf7ae25..24a8bf9ab84b 100644
--- a/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/User.java
@@ -301,10 +301,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/Category.java
index 23f263e87cdf..00bee6b2603b 100644
--- a/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/Category.java
@@ -126,10 +126,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/ModelApiResponse.java
index 33d8a328192c..a36a10fd8504 100644
--- a/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -157,10 +157,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/Order.java
index 76c1d4ce9f5d..5b93f2588ac8 100644
--- a/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/Order.java
@@ -283,10 +283,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/Pet.java
index 96c829c94ad8..a96cfd7e3f8d 100644
--- a/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/Pet.java
@@ -324,10 +324,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/Tag.java
index 3cf3cde67dbd..7dfa82af90e8 100644
--- a/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/Tag.java
@@ -126,10 +126,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/User.java b/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/User.java
index 181d22b55dea..dd221d81e20f 100644
--- a/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/server/petstore/springboot-4/src/main/java/org/openapitools/model/User.java
@@ -300,10 +300,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index 9bed3605a83a..df23b2e0518f 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index f99436d96a05..6455b1d28477 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index a0bd52301143..cf9ce0f5e925 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index a6be2fb360ac..3d7389bec4c9 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -415,10 +415,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index ce5fca38d97e..3bdc569be02e 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index 75b6411f9486..0848aa710a2e 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index 2f79b622e77d..129dd92b5337 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index a398997f37f3..143e46a8644e 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Animal.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Animal.java
index 60c1ec48fa73..24e08237647d 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Animal.java
@@ -126,10 +126,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index f03af73fd905..eeae40cafa74 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -89,10 +89,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 47cfb85cee87..1b5d034f4ac8 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -89,10 +89,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayTest.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayTest.java
index 994e26756e0e..5951b8f4f981 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayTest.java
@@ -157,10 +157,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/BigCat.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/BigCat.java
index c6e52675065f..f94bf89317f0 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/BigCat.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/BigCat.java
@@ -149,10 +149,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Capitalization.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Capitalization.java
index 65e6a969342c..afedf33fe0ba 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Capitalization.java
@@ -201,10 +201,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Cat.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Cat.java
index ab5710d450e5..9612eb31c5c4 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Cat.java
@@ -112,10 +112,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Category.java
index e807ddd8289e..ecdf126c9eda 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Category.java
@@ -112,10 +112,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ChildWithNullable.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ChildWithNullable.java
index 3378761ed1e9..01cc7eb0462e 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ChildWithNullable.java
@@ -107,10 +107,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ClassModel.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ClassModel.java
index 9f97de621a29..3b17108cd459 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ClassModel.java
@@ -77,10 +77,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Client.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Client.java
index ad6d1b9c0d99..7f3a323e6af1 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Client.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Client.java
@@ -76,10 +76,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ContainerDefaultValue.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ContainerDefaultValue.java
index de6eaef4c62f..2386137fecb5 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ContainerDefaultValue.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ContainerDefaultValue.java
@@ -213,10 +213,7 @@ public class ContainerDefaultValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Dog.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Dog.java
index acaff69d979a..36c65b313657 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Dog.java
@@ -104,10 +104,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumArrays.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumArrays.java
index 6879efae982d..1c6836270e59 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumArrays.java
@@ -184,10 +184,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumTest.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumTest.java
index b5583270684c..3d3b901e796d 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumTest.java
@@ -335,10 +335,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/File.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/File.java
index 70b59bd54553..3c808c2564fd 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/File.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/File.java
@@ -77,10 +77,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index 2e4d091a2030..b1da5f0f051d 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -114,10 +114,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FormatTest.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FormatTest.java
index b5970a92765f..bce3371774c1 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FormatTest.java
@@ -435,10 +435,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 7f88fb964a28..9e99407cc172 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -103,10 +103,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/MapTest.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/MapTest.java
index 1f4517b1d4d0..0df5143e02ae 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/MapTest.java
@@ -225,10 +225,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 1e69f24f03c5..a2b9f47bf9ca 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -142,10 +142,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Model200Response.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Model200Response.java
index ff1f86102e2e..c750a0d6534e 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Model200Response.java
@@ -104,10 +104,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelApiResponse.java
index 435055a10a58..f4bc1158e557 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -128,10 +128,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelList.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelList.java
index 34f55886cc98..60a860c7e5a6 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelList.java
@@ -78,10 +78,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelReturn.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelReturn.java
index 50ef51c9cbf5..e1062706a03f 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelReturn.java
@@ -79,10 +79,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Name.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Name.java
index 5ed451ca3a24..1ac9b0316cfb 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Name.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Name.java
@@ -163,10 +163,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/NullableMapProperty.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/NullableMapProperty.java
index 7f51e3098f2a..c7d431471e4d 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/NullableMapProperty.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/NullableMapProperty.java
@@ -100,10 +100,7 @@ public class NullableMapProperty {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/NumberOnly.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/NumberOnly.java
index ada5eb7bc169..24f388d18059 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/NumberOnly.java
@@ -77,10 +77,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Order.java
index d556a66ac5fc..a8a085046bed 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Order.java
@@ -242,10 +242,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/OuterComposite.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/OuterComposite.java
index 0a9dd63af928..f33e0a655695 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/OuterComposite.java
@@ -127,10 +127,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ParentWithNullable.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ParentWithNullable.java
index b49d7563a96e..7c079520417f 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ParentWithNullable.java
@@ -160,10 +160,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Pet.java
index b856d9a3c914..5f1acaaec695 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Pet.java
@@ -285,10 +285,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index 31d7faf6874e..8ca5a82f9c01 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -101,10 +101,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
index ac5973a769b5..064c39c2d87e 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
@@ -151,10 +151,7 @@ public class ResponseObjectWithDifferentFieldNames {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/SpecialModelName.java
index 0e98f6caaae8..d4ab4718139c 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -78,10 +78,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Tag.java
index 10e80a133066..ece3f449fa18 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Tag.java
@@ -101,10 +101,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 77977aa44e73..858ed5d043b1 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -204,10 +204,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/TypeHolderExample.java
index dc0d7259d244..c1d22cceb21c 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -230,10 +230,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/User.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/User.java
index eabdbbb318cc..1e26e2d0fc35 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/User.java
@@ -251,10 +251,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/XmlItem.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/XmlItem.java
index 4fa5151512af..bb65cd50c02f 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/XmlItem.java
@@ -861,10 +861,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index 9bed3605a83a..df23b2e0518f 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index f99436d96a05..6455b1d28477 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index a0bd52301143..cf9ce0f5e925 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index a6be2fb360ac..3d7389bec4c9 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -415,10 +415,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index ce5fca38d97e..3bdc569be02e 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index 75b6411f9486..0848aa710a2e 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index 2f79b622e77d..129dd92b5337 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index a398997f37f3..143e46a8644e 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Animal.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Animal.java
index 60c1ec48fa73..24e08237647d 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Animal.java
@@ -126,10 +126,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index f03af73fd905..eeae40cafa74 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -89,10 +89,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 47cfb85cee87..1b5d034f4ac8 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -89,10 +89,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayTest.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayTest.java
index 994e26756e0e..5951b8f4f981 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayTest.java
@@ -157,10 +157,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/BigCat.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/BigCat.java
index c6e52675065f..f94bf89317f0 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/BigCat.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/BigCat.java
@@ -149,10 +149,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Capitalization.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Capitalization.java
index 65e6a969342c..afedf33fe0ba 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Capitalization.java
@@ -201,10 +201,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Cat.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Cat.java
index ab5710d450e5..9612eb31c5c4 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Cat.java
@@ -112,10 +112,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Category.java
index e807ddd8289e..ecdf126c9eda 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Category.java
@@ -112,10 +112,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ChildWithNullable.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ChildWithNullable.java
index 3378761ed1e9..01cc7eb0462e 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ChildWithNullable.java
@@ -107,10 +107,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ClassModel.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ClassModel.java
index 9f97de621a29..3b17108cd459 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ClassModel.java
@@ -77,10 +77,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Client.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Client.java
index ad6d1b9c0d99..7f3a323e6af1 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Client.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Client.java
@@ -76,10 +76,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ContainerDefaultValue.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ContainerDefaultValue.java
index de6eaef4c62f..2386137fecb5 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ContainerDefaultValue.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ContainerDefaultValue.java
@@ -213,10 +213,7 @@ public class ContainerDefaultValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Dog.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Dog.java
index acaff69d979a..36c65b313657 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Dog.java
@@ -104,10 +104,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumArrays.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumArrays.java
index 6879efae982d..1c6836270e59 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumArrays.java
@@ -184,10 +184,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumTest.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumTest.java
index b5583270684c..3d3b901e796d 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumTest.java
@@ -335,10 +335,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/File.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/File.java
index 70b59bd54553..3c808c2564fd 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/File.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/File.java
@@ -77,10 +77,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index 2e4d091a2030..b1da5f0f051d 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -114,10 +114,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FormatTest.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FormatTest.java
index b5970a92765f..bce3371774c1 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FormatTest.java
@@ -435,10 +435,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 7f88fb964a28..9e99407cc172 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -103,10 +103,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/MapTest.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/MapTest.java
index 1f4517b1d4d0..0df5143e02ae 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/MapTest.java
@@ -225,10 +225,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 1e69f24f03c5..a2b9f47bf9ca 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -142,10 +142,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Model200Response.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Model200Response.java
index ff1f86102e2e..c750a0d6534e 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Model200Response.java
@@ -104,10 +104,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelApiResponse.java
index 435055a10a58..f4bc1158e557 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -128,10 +128,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelList.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelList.java
index 34f55886cc98..60a860c7e5a6 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelList.java
@@ -78,10 +78,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelReturn.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelReturn.java
index 50ef51c9cbf5..e1062706a03f 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelReturn.java
@@ -79,10 +79,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Name.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Name.java
index 5ed451ca3a24..1ac9b0316cfb 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Name.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Name.java
@@ -163,10 +163,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/NullableMapProperty.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/NullableMapProperty.java
index 7f51e3098f2a..c7d431471e4d 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/NullableMapProperty.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/NullableMapProperty.java
@@ -100,10 +100,7 @@ public class NullableMapProperty {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/NumberOnly.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/NumberOnly.java
index ada5eb7bc169..24f388d18059 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/NumberOnly.java
@@ -77,10 +77,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Order.java
index d556a66ac5fc..a8a085046bed 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Order.java
@@ -242,10 +242,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/OuterComposite.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/OuterComposite.java
index 0a9dd63af928..f33e0a655695 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/OuterComposite.java
@@ -127,10 +127,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ParentWithNullable.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ParentWithNullable.java
index b49d7563a96e..7c079520417f 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ParentWithNullable.java
@@ -160,10 +160,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Pet.java
index b856d9a3c914..5f1acaaec695 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Pet.java
@@ -285,10 +285,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index 31d7faf6874e..8ca5a82f9c01 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -101,10 +101,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
index ac5973a769b5..064c39c2d87e 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
@@ -151,10 +151,7 @@ public class ResponseObjectWithDifferentFieldNames {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/SpecialModelName.java
index 0e98f6caaae8..d4ab4718139c 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -78,10 +78,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Tag.java
index 10e80a133066..ece3f449fa18 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Tag.java
@@ -101,10 +101,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 77977aa44e73..858ed5d043b1 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -204,10 +204,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/TypeHolderExample.java
index dc0d7259d244..c1d22cceb21c 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -230,10 +230,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/User.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/User.java
index eabdbbb318cc..1e26e2d0fc35 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/User.java
@@ -251,10 +251,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/XmlItem.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/XmlItem.java
index 4fa5151512af..bb65cd50c02f 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/XmlItem.java
@@ -861,10 +861,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Category.java
index b05ab761a644..9a7feeb55b19 100644
--- a/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Category.java
@@ -98,10 +98,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/ModelApiResponse.java
index 0dd252ceb3cf..aa00799ab36d 100644
--- a/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -124,10 +124,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Order.java
index 3a0302f27cfd..d4d12661ee2f 100644
--- a/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Order.java
@@ -235,10 +235,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Pet.java
index e1f842160c3b..45029db1b343 100644
--- a/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Pet.java
@@ -274,10 +274,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Tag.java
index 04c51972c07e..24bff58ed462 100644
--- a/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Tag.java
@@ -98,10 +98,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/User.java b/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/User.java
index 29a76a29e3e0..ad99440de942 100644
--- a/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/User.java
@@ -242,10 +242,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Category.java b/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Category.java
index a83df46e1b37..24b392308f53 100644
--- a/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Category.java
+++ b/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Category.java
@@ -102,10 +102,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/ModelApiResponse.java
index fd3c591671e8..edeb1f66019e 100644
--- a/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Order.java b/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Order.java
index 47c00ea1a56a..0c245c5f9f2c 100644
--- a/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Order.java
+++ b/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Pet.java
index 0ed1300e039b..06067f7a0c84 100644
--- a/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Pet.java
@@ -282,10 +282,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Tag.java b/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Tag.java
index f8a38e352878..1f94a8ef63aa 100644
--- a/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/User.java b/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/User.java
index 4e55c123cbf5..ae9bf7482766 100644
--- a/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/User.java
+++ b/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/others/java-helidon-server/v3/mp-format-test/src/main/java/org/openapitools/server/model/FormatTest.java b/samples/server/others/java-helidon-server/v3/mp-format-test/src/main/java/org/openapitools/server/model/FormatTest.java
index fe39d1787b11..b7dc6c64c5f5 100644
--- a/samples/server/others/java-helidon-server/v3/mp-format-test/src/main/java/org/openapitools/server/model/FormatTest.java
+++ b/samples/server/others/java-helidon-server/v3/mp-format-test/src/main/java/org/openapitools/server/model/FormatTest.java
@@ -65,10 +65,7 @@ public class FormatTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/others/java-helidon-server/v4/mp-format-test/src/main/java/org/openapitools/server/model/FormatTest.java b/samples/server/others/java-helidon-server/v4/mp-format-test/src/main/java/org/openapitools/server/model/FormatTest.java
index fe39d1787b11..b7dc6c64c5f5 100644
--- a/samples/server/others/java-helidon-server/v4/mp-format-test/src/main/java/org/openapitools/server/model/FormatTest.java
+++ b/samples/server/others/java-helidon-server/v4/mp-format-test/src/main/java/org/openapitools/server/model/FormatTest.java
@@ -65,10 +65,7 @@ public class FormatTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Category.java
index d87f06ba9a5b..ef95b82b6926 100644
--- a/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Category.java
@@ -109,10 +109,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/ModelApiResponse.java
index 4a06ca4b8227..d5716e7d4416 100644
--- a/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -136,10 +136,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Order.java
index 73ff0072e046..818ccdbaa4a9 100644
--- a/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Order.java
@@ -250,10 +250,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Pet.java
index 3419f45a8216..82df6646dd56 100644
--- a/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Pet.java
@@ -291,10 +291,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Tag.java
index fab96183a6ab..e422fc79a4f3 100644
--- a/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Tag.java
@@ -109,10 +109,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/User.java
index 05bf65bceede..fc077ddebaf4 100644
--- a/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/User.java
@@ -259,10 +259,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/Category.java b/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/Category.java
index f948a0718112..e7c1db6531a4 100644
--- a/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/Category.java
+++ b/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/Category.java
@@ -79,9 +79,6 @@ public class Category implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/ModelApiResponse.java b/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/ModelApiResponse.java
index 6376cdc48c92..71c8a8e8a462 100644
--- a/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/ModelApiResponse.java
+++ b/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/ModelApiResponse.java
@@ -96,9 +96,6 @@ public class ModelApiResponse implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/Order.java b/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/Order.java
index 2b446741faa4..058f72b6b973 100644
--- a/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/Order.java
+++ b/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/Order.java
@@ -151,9 +151,6 @@ public class Order implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/Pet.java b/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/Pet.java
index 74061578a70c..5b2da430c675 100644
--- a/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/Pet.java
+++ b/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/Pet.java
@@ -153,9 +153,6 @@ public class Pet implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/Tag.java b/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/Tag.java
index b299160a6d7d..a0e42b155045 100644
--- a/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/Tag.java
+++ b/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/Tag.java
@@ -79,9 +79,6 @@ public class Tag implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/User.java b/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/User.java
index 22611dc891a1..e746fcc04ab9 100644
--- a/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/User.java
+++ b/samples/server/petstore/java-dubbo/src/main/java/org/openapitools/example/model/User.java
@@ -184,9 +184,6 @@ public class User implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
index f5c1e01d9e11..cfdf8960ff63 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
@@ -99,10 +99,7 @@ public class AdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
index 40e102a9cb32..8bba5423d39b 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
@@ -90,10 +90,7 @@ public class AllOfWithSingleRef  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Animal.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Animal.java
index 3a90afbad85e..42336e8c2f59 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Animal.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Animal.java
@@ -91,10 +91,7 @@ public class Animal  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
index 0a02e0ec0412..49925ba5eed7 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
@@ -73,10 +73,7 @@ public class ArrayOfArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
index 65521fb4507b..13b3641f9d1a 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
@@ -73,10 +73,7 @@ public class ArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ArrayTest.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ArrayTest.java
index d599c7993066..a8746b153567 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ArrayTest.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ArrayTest.java
@@ -129,10 +129,7 @@ public class ArrayTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Capitalization.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Capitalization.java
index 933d2f15d5f9..96d5e68d1657 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Capitalization.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Capitalization.java
@@ -182,10 +182,7 @@ public class Capitalization  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Cat.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Cat.java
index 78534303e0ff..5251c37291c3 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Cat.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Cat.java
@@ -68,10 +68,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Category.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Category.java
index e92a984945d0..4c81e588498b 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Category.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Category.java
@@ -88,10 +88,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ChildWithNullable.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ChildWithNullable.java
index abe443a27f85..2d52e66a1ff4 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ChildWithNullable.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ChildWithNullable.java
@@ -71,10 +71,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ClassModel.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ClassModel.java
index a0b5f1b7eb02..e61996b6145f 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ClassModel.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ClassModel.java
@@ -67,10 +67,7 @@ public class ClassModel  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Client.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Client.java
index 522166364aee..9af89fdd5d9c 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Client.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Client.java
@@ -64,10 +64,7 @@ public class Client  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/DeprecatedObject.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/DeprecatedObject.java
index 0ea4aa39023d..916ea473ad4f 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/DeprecatedObject.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/DeprecatedObject.java
@@ -64,10 +64,7 @@ public class DeprecatedObject  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Dog.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Dog.java
index e0f8e5a79b42..d5e8528f0b2e 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Dog.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Dog.java
@@ -68,10 +68,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/EnumArrays.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/EnumArrays.java
index 0b7086059457..5b3b4df22b35 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/EnumArrays.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/EnumArrays.java
@@ -191,10 +191,7 @@ public enum ArrayEnumEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/EnumTest.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/EnumTest.java
index 9476edffbf91..c4c705a70ecd 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/EnumTest.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/EnumTest.java
@@ -422,10 +422,7 @@ public enum EnumNumberEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
index 2b98d3cff5c8..08d69f77ac86 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
@@ -96,10 +96,7 @@ public class FakeBigDecimalMap200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
index 1b47816ef284..fd65992c98eb 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
@@ -96,10 +96,7 @@ public class FileSchemaTestClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Foo.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Foo.java
index 66c97424c43b..1e66dedecef2 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Foo.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Foo.java
@@ -64,10 +64,7 @@ public class Foo  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
index 2536010aaeb3..c893507f5b71 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
@@ -66,10 +66,7 @@ public class FooGetDefaultResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/FormatTest.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/FormatTest.java
index c98c85ccbebb..7c6556fc74cb 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/FormatTest.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/FormatTest.java
@@ -435,10 +435,7 @@ public class FormatTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
index 82f9d533067b..2799ce481cdd 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
@@ -80,10 +80,7 @@ public class HasOnlyReadOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/HealthCheckResult.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/HealthCheckResult.java
index 7ac79cd6f901..159779649e54 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/HealthCheckResult.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/HealthCheckResult.java
@@ -68,10 +68,7 @@ public class HealthCheckResult  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/MapTest.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/MapTest.java
index 4a446f75cf36..927e6ba9fb8a 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/MapTest.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/MapTest.java
@@ -204,10 +204,7 @@ public enum InnerEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 1d04eaf6c945..24c72d506a51 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -120,10 +120,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Model200Response.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Model200Response.java
index a091e534c321..3e334fb0eca3 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Model200Response.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Model200Response.java
@@ -91,10 +91,7 @@ public class Model200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ModelApiResponse.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ModelApiResponse.java
index 9d01d1753e1f..75a44cf97943 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ModelApiResponse.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ModelApiResponse.java
@@ -111,10 +111,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ModelFile.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ModelFile.java
index 432f843889c8..dfa5ce4b3ed9 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ModelFile.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ModelFile.java
@@ -71,10 +71,7 @@ public class ModelFile  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ModelList.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ModelList.java
index a8e0e3a4b0b4..b3633d4bf483 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ModelList.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ModelList.java
@@ -65,10 +65,7 @@ public class ModelList  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ModelReturn.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ModelReturn.java
index c37c75a2bf20..80bfba7f08cf 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ModelReturn.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ModelReturn.java
@@ -68,10 +68,7 @@ public class ModelReturn  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Name.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Name.java
index bb51b8097427..25fc33bac302 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Name.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Name.java
@@ -129,10 +129,7 @@ public class Name  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/NullableClass.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/NullableClass.java
index dc00c081d15c..997e6f4c35a1 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/NullableClass.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/NullableClass.java
@@ -356,10 +356,7 @@ public class NullableClass extends HashMap<String, Object> {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/NumberOnly.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/NumberOnly.java
index e0761ba551b4..70145b601adb 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/NumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/NumberOnly.java
@@ -65,10 +65,7 @@ public class NumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
index dc24a224465a..b5d19904e122 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
@@ -149,10 +149,7 @@ public class ObjectWithDeprecatedFields  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Order.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Order.java
index 707cdd3797f9..b087a228c28b 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Order.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Order.java
@@ -232,10 +232,7 @@ public enum StatusEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/OuterComposite.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/OuterComposite.java
index 7d1630e2f525..df9b5dab44b5 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/OuterComposite.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/OuterComposite.java
@@ -111,10 +111,7 @@ public class OuterComposite  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
index 552f07ecc3ad..0f25ab103461 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
@@ -68,10 +68,7 @@ public class OuterObjectWithEnumProperty  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ParentWithNullable.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ParentWithNullable.java
index 67de84d392df..1a7c90a00e96 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ParentWithNullable.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ParentWithNullable.java
@@ -140,10 +140,7 @@ public enum TypeEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Pet.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Pet.java
index f58096fff738..9bbc1a2f45e0 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Pet.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Pet.java
@@ -252,10 +252,7 @@ public enum StatusEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
index 3294db20f659..97c5c448adb2 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
@@ -87,10 +87,7 @@ public class ReadOnlyFirst  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/SpecialModelName.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/SpecialModelName.java
index 333b4dd35caf..b958ca498edf 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/SpecialModelName.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/SpecialModelName.java
@@ -65,10 +65,7 @@ public class SpecialModelName  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Tag.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Tag.java
index 3be9794db142..bbddd249d5c1 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Tag.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/Tag.java
@@ -87,10 +87,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
index abbeb6e6130f..7766fb3e0634 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -67,10 +67,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/User.java b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/User.java
index 07ab5974ee50..090d2c243952 100644
--- a/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/User.java
+++ b/samples/server/petstore/java-helidon-server/v3/mp/src/main/java/org/openapitools/server/model/User.java
@@ -228,10 +228,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
index 1266dac5d907..137de19a0591 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
@@ -78,10 +78,7 @@ public class AdditionalPropertiesClass   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
index 63eeb7f67afb..bc9c763d4252 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
@@ -79,10 +79,7 @@ public class AllOfWithSingleRef   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Animal.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Animal.java
index 548edc48a8a8..7d9715022a2e 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Animal.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Animal.java
@@ -79,10 +79,7 @@ public class Animal   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
index 83c75a242e8e..ca47a0ebb266 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
@@ -63,10 +63,7 @@ public class ArrayOfArrayOfNumberOnly   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
index 971fb516ba0c..88378ff5947e 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
@@ -63,10 +63,7 @@ public class ArrayOfNumberOnly   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayTest.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayTest.java
index d94cad1da9a3..66bc4141a5b4 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayTest.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayTest.java
@@ -97,10 +97,7 @@ public class ArrayTest   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Capitalization.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Capitalization.java
index 942f62d57fbc..8422bf244c26 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Capitalization.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Capitalization.java
@@ -144,10 +144,7 @@ public class Capitalization   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Cat.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Cat.java
index d0d01e632a5e..b8149dd25f56 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Cat.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Cat.java
@@ -63,10 +63,7 @@ public class Cat extends Animal  {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Category.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Category.java
index ce9f854b3b91..6a506f1786b6 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Category.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Category.java
@@ -76,10 +76,7 @@ public class Category   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ChildWithNullable.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ChildWithNullable.java
index ea4c963b2b56..e3f5db31c840 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ChildWithNullable.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ChildWithNullable.java
@@ -66,10 +66,7 @@ public class ChildWithNullable extends ParentWithNullable  {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ClassModel.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ClassModel.java
index 806a179ba10a..bfe60409c12d 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ClassModel.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ClassModel.java
@@ -61,10 +61,7 @@ public class ClassModel   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Client.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Client.java
index 3b500ac997ee..7b29c5f4dfc7 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Client.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Client.java
@@ -59,10 +59,7 @@ public class Client   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/DeprecatedObject.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/DeprecatedObject.java
index 4e2b7051130c..f4174788bfb8 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/DeprecatedObject.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/DeprecatedObject.java
@@ -59,10 +59,7 @@ public class DeprecatedObject   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Dog.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Dog.java
index f935612575ee..ee9c075dac4c 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Dog.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Dog.java
@@ -63,10 +63,7 @@ public class Dog extends Animal  {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/EnumArrays.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/EnumArrays.java
index 29d6ebaa8fb4..9ea77a9034e7 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/EnumArrays.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/EnumArrays.java
@@ -155,10 +155,7 @@ public class EnumArrays   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/EnumTest.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/EnumTest.java
index d2d7d27c9414..c5158fca9f87 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/EnumTest.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/EnumTest.java
@@ -336,10 +336,7 @@ public class EnumTest   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
index b50b92931cf5..8760e968b923 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
@@ -80,10 +80,7 @@ public class FakeBigDecimalMap200Response   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
index 2b6964db9dec..97f7dee2940e 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
@@ -80,10 +80,7 @@ public class FileSchemaTestClass   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Foo.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Foo.java
index e02a00803c22..d006f5faa70b 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Foo.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Foo.java
@@ -59,10 +59,7 @@ public class Foo   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
index 40f8d5855417..df5e23fe5da7 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
@@ -61,10 +61,7 @@ public class FooGetDefaultResponse   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FormatTest.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FormatTest.java
index 92e3aef3e80d..504fbf6060c3 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FormatTest.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FormatTest.java
@@ -330,10 +330,7 @@ public class FormatTest   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
index 50c41f059e3b..4c793c3eeb47 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
@@ -77,10 +77,7 @@ public class HasOnlyReadOnly   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/HealthCheckResult.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/HealthCheckResult.java
index 5b865aa0e3f3..96a10e97b09e 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/HealthCheckResult.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/HealthCheckResult.java
@@ -62,10 +62,7 @@ public class HealthCheckResult   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/MapTest.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/MapTest.java
index f8051c6e3e45..4db323d40fcb 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/MapTest.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/MapTest.java
@@ -151,10 +151,7 @@ public class MapTest   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 9f2e5dc7bbef..b5f6c285a303 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -98,10 +98,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Model200Response.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Model200Response.java
index 28f6bd2cdac0..055d1f78d476 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Model200Response.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Model200Response.java
@@ -79,10 +79,7 @@ public class Model200Response   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ModelApiResponse.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ModelApiResponse.java
index 81a468f1af79..9022022b9544 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ModelApiResponse.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ModelApiResponse.java
@@ -94,10 +94,7 @@ public class ModelApiResponse   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ModelFile.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ModelFile.java
index 6743c641a001..916ce4c96d35 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ModelFile.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ModelFile.java
@@ -62,10 +62,7 @@ public class ModelFile   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ModelList.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ModelList.java
index 88000df9959e..c3aea2a26bf0 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ModelList.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ModelList.java
@@ -60,10 +60,7 @@ public class ModelList   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ModelReturn.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ModelReturn.java
index a11d5e2b4e49..1f53f62880e2 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ModelReturn.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ModelReturn.java
@@ -62,10 +62,7 @@ public class ModelReturn   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Name.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Name.java
index a3524465b284..339cc7be5e5f 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Name.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Name.java
@@ -112,10 +112,7 @@ public class Name   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/NullableClass.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/NullableClass.java
index 11e7e2ec0fd0..b5d03aee1364 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/NullableClass.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/NullableClass.java
@@ -255,10 +255,7 @@ public class NullableClass extends HashMap<String, Object>  {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/NumberOnly.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/NumberOnly.java
index 7caf3c857f39..5de20b5e1f36 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/NumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/NumberOnly.java
@@ -60,10 +60,7 @@ public class NumberOnly   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
index 83bc634c1d6b..fbd3be5598e9 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
@@ -115,10 +115,7 @@ public class ObjectWithDeprecatedFields   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Order.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Order.java
index 0ca5e240f6f6..93886363cfd1 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Order.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Order.java
@@ -185,10 +185,7 @@ public class Order   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/OuterComposite.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/OuterComposite.java
index 696e549642d2..a90c38e4c535 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/OuterComposite.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/OuterComposite.java
@@ -94,10 +94,7 @@ public class OuterComposite   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
index cd57e792975e..8fe2aa89dd61 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
@@ -62,10 +62,7 @@ public class OuterObjectWithEnumProperty   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ParentWithNullable.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ParentWithNullable.java
index e458a6ed3400..af5497566694 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ParentWithNullable.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ParentWithNullable.java
@@ -118,10 +118,7 @@ public class ParentWithNullable   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Pet.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Pet.java
index 671a9be156dc..3ccffcd5b110 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Pet.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Pet.java
@@ -192,10 +192,7 @@ public class Pet   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
index 6e9d1f16fb1d..e2256af87974 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
@@ -76,10 +76,7 @@ public class ReadOnlyFirst   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/SpecialModelName.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/SpecialModelName.java
index 9c14659f899a..6016175f8ff6 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/SpecialModelName.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/SpecialModelName.java
@@ -60,10 +60,7 @@ public class SpecialModelName   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Tag.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Tag.java
index e0d425d782e2..932fe2c5e5e4 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Tag.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Tag.java
@@ -76,10 +76,7 @@ public class Tag   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 499fa5013feb..3da9bc6713f4 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -62,10 +62,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/User.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/User.java
index 9decbea90472..5d1164c694e9 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/User.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/User.java
@@ -178,10 +178,7 @@ public class User   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
index f5c1e01d9e11..cfdf8960ff63 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
@@ -99,10 +99,7 @@ public class AdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
index 40e102a9cb32..8bba5423d39b 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
@@ -90,10 +90,7 @@ public class AllOfWithSingleRef  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Animal.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Animal.java
index 3a90afbad85e..42336e8c2f59 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Animal.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Animal.java
@@ -91,10 +91,7 @@ public class Animal  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
index 0a02e0ec0412..49925ba5eed7 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
@@ -73,10 +73,7 @@ public class ArrayOfArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
index 65521fb4507b..13b3641f9d1a 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
@@ -73,10 +73,7 @@ public class ArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ArrayTest.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ArrayTest.java
index d599c7993066..a8746b153567 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ArrayTest.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ArrayTest.java
@@ -129,10 +129,7 @@ public class ArrayTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Capitalization.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Capitalization.java
index 933d2f15d5f9..96d5e68d1657 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Capitalization.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Capitalization.java
@@ -182,10 +182,7 @@ public class Capitalization  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Cat.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Cat.java
index 78534303e0ff..5251c37291c3 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Cat.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Cat.java
@@ -68,10 +68,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Category.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Category.java
index e92a984945d0..4c81e588498b 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Category.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Category.java
@@ -88,10 +88,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ChildWithNullable.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ChildWithNullable.java
index abe443a27f85..2d52e66a1ff4 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ChildWithNullable.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ChildWithNullable.java
@@ -71,10 +71,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ClassModel.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ClassModel.java
index a0b5f1b7eb02..e61996b6145f 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ClassModel.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ClassModel.java
@@ -67,10 +67,7 @@ public class ClassModel  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Client.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Client.java
index 522166364aee..9af89fdd5d9c 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Client.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Client.java
@@ -64,10 +64,7 @@ public class Client  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/DeprecatedObject.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/DeprecatedObject.java
index 0ea4aa39023d..916ea473ad4f 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/DeprecatedObject.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/DeprecatedObject.java
@@ -64,10 +64,7 @@ public class DeprecatedObject  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Dog.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Dog.java
index e0f8e5a79b42..d5e8528f0b2e 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Dog.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Dog.java
@@ -68,10 +68,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/EnumArrays.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/EnumArrays.java
index 0b7086059457..5b3b4df22b35 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/EnumArrays.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/EnumArrays.java
@@ -191,10 +191,7 @@ public enum ArrayEnumEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/EnumTest.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/EnumTest.java
index 9476edffbf91..c4c705a70ecd 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/EnumTest.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/EnumTest.java
@@ -422,10 +422,7 @@ public enum EnumNumberEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
index 2b98d3cff5c8..08d69f77ac86 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
@@ -96,10 +96,7 @@ public class FakeBigDecimalMap200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
index 1b47816ef284..fd65992c98eb 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
@@ -96,10 +96,7 @@ public class FileSchemaTestClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Foo.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Foo.java
index 66c97424c43b..1e66dedecef2 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Foo.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Foo.java
@@ -64,10 +64,7 @@ public class Foo  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
index 2536010aaeb3..c893507f5b71 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
@@ -66,10 +66,7 @@ public class FooGetDefaultResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/FormatTest.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/FormatTest.java
index c98c85ccbebb..7c6556fc74cb 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/FormatTest.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/FormatTest.java
@@ -435,10 +435,7 @@ public class FormatTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
index 82f9d533067b..2799ce481cdd 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
@@ -80,10 +80,7 @@ public class HasOnlyReadOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/HealthCheckResult.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/HealthCheckResult.java
index 7ac79cd6f901..159779649e54 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/HealthCheckResult.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/HealthCheckResult.java
@@ -68,10 +68,7 @@ public class HealthCheckResult  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/MapTest.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/MapTest.java
index 4a446f75cf36..927e6ba9fb8a 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/MapTest.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/MapTest.java
@@ -204,10 +204,7 @@ public enum InnerEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 1d04eaf6c945..24c72d506a51 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -120,10 +120,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Model200Response.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Model200Response.java
index a091e534c321..3e334fb0eca3 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Model200Response.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Model200Response.java
@@ -91,10 +91,7 @@ public class Model200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ModelApiResponse.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ModelApiResponse.java
index 9d01d1753e1f..75a44cf97943 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ModelApiResponse.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ModelApiResponse.java
@@ -111,10 +111,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ModelFile.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ModelFile.java
index 432f843889c8..dfa5ce4b3ed9 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ModelFile.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ModelFile.java
@@ -71,10 +71,7 @@ public class ModelFile  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ModelList.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ModelList.java
index a8e0e3a4b0b4..b3633d4bf483 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ModelList.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ModelList.java
@@ -65,10 +65,7 @@ public class ModelList  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ModelReturn.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ModelReturn.java
index c37c75a2bf20..80bfba7f08cf 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ModelReturn.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ModelReturn.java
@@ -68,10 +68,7 @@ public class ModelReturn  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Name.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Name.java
index bb51b8097427..25fc33bac302 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Name.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Name.java
@@ -129,10 +129,7 @@ public class Name  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/NullableClass.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/NullableClass.java
index dc00c081d15c..997e6f4c35a1 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/NullableClass.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/NullableClass.java
@@ -356,10 +356,7 @@ public class NullableClass extends HashMap<String, Object> {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/NumberOnly.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/NumberOnly.java
index e0761ba551b4..70145b601adb 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/NumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/NumberOnly.java
@@ -65,10 +65,7 @@ public class NumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
index dc24a224465a..b5d19904e122 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
@@ -149,10 +149,7 @@ public class ObjectWithDeprecatedFields  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Order.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Order.java
index 707cdd3797f9..b087a228c28b 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Order.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Order.java
@@ -232,10 +232,7 @@ public enum StatusEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/OuterComposite.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/OuterComposite.java
index 7d1630e2f525..df9b5dab44b5 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/OuterComposite.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/OuterComposite.java
@@ -111,10 +111,7 @@ public class OuterComposite  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
index 552f07ecc3ad..0f25ab103461 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
@@ -68,10 +68,7 @@ public class OuterObjectWithEnumProperty  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ParentWithNullable.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ParentWithNullable.java
index 67de84d392df..1a7c90a00e96 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ParentWithNullable.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ParentWithNullable.java
@@ -140,10 +140,7 @@ public enum TypeEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Pet.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Pet.java
index f58096fff738..9bbc1a2f45e0 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Pet.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Pet.java
@@ -252,10 +252,7 @@ public enum StatusEnum {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
index 3294db20f659..97c5c448adb2 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
@@ -87,10 +87,7 @@ public class ReadOnlyFirst  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/SpecialModelName.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/SpecialModelName.java
index 333b4dd35caf..b958ca498edf 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/SpecialModelName.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/SpecialModelName.java
@@ -65,10 +65,7 @@ public class SpecialModelName  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Tag.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Tag.java
index 3be9794db142..bbddd249d5c1 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Tag.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/Tag.java
@@ -87,10 +87,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
index abbeb6e6130f..7766fb3e0634 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -67,10 +67,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/User.java b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/User.java
index 07ab5974ee50..090d2c243952 100644
--- a/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/User.java
+++ b/samples/server/petstore/java-helidon-server/v4/mp/src/main/java/org/openapitools/server/model/User.java
@@ -228,10 +228,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
index 1266dac5d907..137de19a0591 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
@@ -78,10 +78,7 @@ public class AdditionalPropertiesClass   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
index 63eeb7f67afb..bc9c763d4252 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
@@ -79,10 +79,7 @@ public class AllOfWithSingleRef   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Animal.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Animal.java
index 548edc48a8a8..7d9715022a2e 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Animal.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Animal.java
@@ -79,10 +79,7 @@ public class Animal   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
index 83c75a242e8e..ca47a0ebb266 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
@@ -63,10 +63,7 @@ public class ArrayOfArrayOfNumberOnly   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
index 971fb516ba0c..88378ff5947e 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
@@ -63,10 +63,7 @@ public class ArrayOfNumberOnly   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ArrayTest.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ArrayTest.java
index d94cad1da9a3..66bc4141a5b4 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ArrayTest.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ArrayTest.java
@@ -97,10 +97,7 @@ public class ArrayTest   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Capitalization.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Capitalization.java
index 942f62d57fbc..8422bf244c26 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Capitalization.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Capitalization.java
@@ -144,10 +144,7 @@ public class Capitalization   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Cat.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Cat.java
index d0d01e632a5e..b8149dd25f56 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Cat.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Cat.java
@@ -63,10 +63,7 @@ public class Cat extends Animal  {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Category.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Category.java
index ce9f854b3b91..6a506f1786b6 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Category.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Category.java
@@ -76,10 +76,7 @@ public class Category   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ChildWithNullable.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ChildWithNullable.java
index ea4c963b2b56..e3f5db31c840 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ChildWithNullable.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ChildWithNullable.java
@@ -66,10 +66,7 @@ public class ChildWithNullable extends ParentWithNullable  {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ClassModel.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ClassModel.java
index 806a179ba10a..bfe60409c12d 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ClassModel.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ClassModel.java
@@ -61,10 +61,7 @@ public class ClassModel   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Client.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Client.java
index 3b500ac997ee..7b29c5f4dfc7 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Client.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Client.java
@@ -59,10 +59,7 @@ public class Client   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/DeprecatedObject.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/DeprecatedObject.java
index 4e2b7051130c..f4174788bfb8 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/DeprecatedObject.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/DeprecatedObject.java
@@ -59,10 +59,7 @@ public class DeprecatedObject   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Dog.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Dog.java
index f935612575ee..ee9c075dac4c 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Dog.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Dog.java
@@ -63,10 +63,7 @@ public class Dog extends Animal  {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/EnumArrays.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/EnumArrays.java
index 29d6ebaa8fb4..9ea77a9034e7 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/EnumArrays.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/EnumArrays.java
@@ -155,10 +155,7 @@ public class EnumArrays   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/EnumTest.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/EnumTest.java
index d2d7d27c9414..c5158fca9f87 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/EnumTest.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/EnumTest.java
@@ -336,10 +336,7 @@ public class EnumTest   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
index b50b92931cf5..8760e968b923 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
@@ -80,10 +80,7 @@ public class FakeBigDecimalMap200Response   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
index 2b6964db9dec..97f7dee2940e 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
@@ -80,10 +80,7 @@ public class FileSchemaTestClass   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Foo.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Foo.java
index e02a00803c22..d006f5faa70b 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Foo.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Foo.java
@@ -59,10 +59,7 @@ public class Foo   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
index 40f8d5855417..df5e23fe5da7 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
@@ -61,10 +61,7 @@ public class FooGetDefaultResponse   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/FormatTest.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/FormatTest.java
index 92e3aef3e80d..504fbf6060c3 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/FormatTest.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/FormatTest.java
@@ -330,10 +330,7 @@ public class FormatTest   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
index 50c41f059e3b..4c793c3eeb47 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
@@ -77,10 +77,7 @@ public class HasOnlyReadOnly   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/HealthCheckResult.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/HealthCheckResult.java
index 5b865aa0e3f3..96a10e97b09e 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/HealthCheckResult.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/HealthCheckResult.java
@@ -62,10 +62,7 @@ public class HealthCheckResult   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/MapTest.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/MapTest.java
index f8051c6e3e45..4db323d40fcb 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/MapTest.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/MapTest.java
@@ -151,10 +151,7 @@ public class MapTest   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 9f2e5dc7bbef..b5f6c285a303 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -98,10 +98,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Model200Response.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Model200Response.java
index 28f6bd2cdac0..055d1f78d476 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Model200Response.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Model200Response.java
@@ -79,10 +79,7 @@ public class Model200Response   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ModelApiResponse.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ModelApiResponse.java
index 81a468f1af79..9022022b9544 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ModelApiResponse.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ModelApiResponse.java
@@ -94,10 +94,7 @@ public class ModelApiResponse   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ModelFile.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ModelFile.java
index 6743c641a001..916ce4c96d35 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ModelFile.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ModelFile.java
@@ -62,10 +62,7 @@ public class ModelFile   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ModelList.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ModelList.java
index 88000df9959e..c3aea2a26bf0 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ModelList.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ModelList.java
@@ -60,10 +60,7 @@ public class ModelList   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ModelReturn.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ModelReturn.java
index a11d5e2b4e49..1f53f62880e2 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ModelReturn.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ModelReturn.java
@@ -62,10 +62,7 @@ public class ModelReturn   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Name.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Name.java
index a3524465b284..339cc7be5e5f 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Name.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Name.java
@@ -112,10 +112,7 @@ public class Name   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/NullableClass.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/NullableClass.java
index 11e7e2ec0fd0..b5d03aee1364 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/NullableClass.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/NullableClass.java
@@ -255,10 +255,7 @@ public class NullableClass extends HashMap<String, Object>  {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/NumberOnly.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/NumberOnly.java
index 7caf3c857f39..5de20b5e1f36 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/NumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/NumberOnly.java
@@ -60,10 +60,7 @@ public class NumberOnly   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
index 83bc634c1d6b..fbd3be5598e9 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
@@ -115,10 +115,7 @@ public class ObjectWithDeprecatedFields   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Order.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Order.java
index 0ca5e240f6f6..93886363cfd1 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Order.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Order.java
@@ -185,10 +185,7 @@ public class Order   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/OuterComposite.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/OuterComposite.java
index 696e549642d2..a90c38e4c535 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/OuterComposite.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/OuterComposite.java
@@ -94,10 +94,7 @@ public class OuterComposite   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
index cd57e792975e..8fe2aa89dd61 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
@@ -62,10 +62,7 @@ public class OuterObjectWithEnumProperty   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ParentWithNullable.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ParentWithNullable.java
index e458a6ed3400..af5497566694 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ParentWithNullable.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ParentWithNullable.java
@@ -118,10 +118,7 @@ public class ParentWithNullable   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Pet.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Pet.java
index 671a9be156dc..3ccffcd5b110 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Pet.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Pet.java
@@ -192,10 +192,7 @@ public class Pet   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
index 6e9d1f16fb1d..e2256af87974 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
@@ -76,10 +76,7 @@ public class ReadOnlyFirst   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/SpecialModelName.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/SpecialModelName.java
index 9c14659f899a..6016175f8ff6 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/SpecialModelName.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/SpecialModelName.java
@@ -60,10 +60,7 @@ public class SpecialModelName   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Tag.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Tag.java
index e0d425d782e2..932fe2c5e5e4 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Tag.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/Tag.java
@@ -76,10 +76,7 @@ public class Tag   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 499fa5013feb..3da9bc6713f4 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -62,10 +62,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/User.java b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/User.java
index 9decbea90472..5d1164c694e9 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/User.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac-group-by-file-path/src/main/java/org/openapitools/server/model/User.java
@@ -178,10 +178,7 @@ public class User   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
index 1266dac5d907..137de19a0591 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
@@ -78,10 +78,7 @@ public class AdditionalPropertiesClass   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
index 63eeb7f67afb..bc9c763d4252 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
@@ -79,10 +79,7 @@ public class AllOfWithSingleRef   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Animal.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Animal.java
index 548edc48a8a8..7d9715022a2e 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Animal.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Animal.java
@@ -79,10 +79,7 @@ public class Animal   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
index 83c75a242e8e..ca47a0ebb266 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
@@ -63,10 +63,7 @@ public class ArrayOfArrayOfNumberOnly   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
index 971fb516ba0c..88378ff5947e 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
@@ -63,10 +63,7 @@ public class ArrayOfNumberOnly   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ArrayTest.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ArrayTest.java
index d94cad1da9a3..66bc4141a5b4 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ArrayTest.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ArrayTest.java
@@ -97,10 +97,7 @@ public class ArrayTest   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Capitalization.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Capitalization.java
index 942f62d57fbc..8422bf244c26 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Capitalization.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Capitalization.java
@@ -144,10 +144,7 @@ public class Capitalization   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Cat.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Cat.java
index d0d01e632a5e..b8149dd25f56 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Cat.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Cat.java
@@ -63,10 +63,7 @@ public class Cat extends Animal  {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Category.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Category.java
index ce9f854b3b91..6a506f1786b6 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Category.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Category.java
@@ -76,10 +76,7 @@ public class Category   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ChildWithNullable.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ChildWithNullable.java
index ea4c963b2b56..e3f5db31c840 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ChildWithNullable.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ChildWithNullable.java
@@ -66,10 +66,7 @@ public class ChildWithNullable extends ParentWithNullable  {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ClassModel.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ClassModel.java
index 806a179ba10a..bfe60409c12d 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ClassModel.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ClassModel.java
@@ -61,10 +61,7 @@ public class ClassModel   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Client.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Client.java
index 3b500ac997ee..7b29c5f4dfc7 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Client.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Client.java
@@ -59,10 +59,7 @@ public class Client   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/DeprecatedObject.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/DeprecatedObject.java
index 4e2b7051130c..f4174788bfb8 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/DeprecatedObject.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/DeprecatedObject.java
@@ -59,10 +59,7 @@ public class DeprecatedObject   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Dog.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Dog.java
index f935612575ee..ee9c075dac4c 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Dog.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Dog.java
@@ -63,10 +63,7 @@ public class Dog extends Animal  {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/EnumArrays.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/EnumArrays.java
index 29d6ebaa8fb4..9ea77a9034e7 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/EnumArrays.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/EnumArrays.java
@@ -155,10 +155,7 @@ public class EnumArrays   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/EnumTest.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/EnumTest.java
index d2d7d27c9414..c5158fca9f87 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/EnumTest.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/EnumTest.java
@@ -336,10 +336,7 @@ public class EnumTest   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
index b50b92931cf5..8760e968b923 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
@@ -80,10 +80,7 @@ public class FakeBigDecimalMap200Response   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
index 2b6964db9dec..97f7dee2940e 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
@@ -80,10 +80,7 @@ public class FileSchemaTestClass   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Foo.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Foo.java
index e02a00803c22..d006f5faa70b 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Foo.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Foo.java
@@ -59,10 +59,7 @@ public class Foo   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
index 40f8d5855417..df5e23fe5da7 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
@@ -61,10 +61,7 @@ public class FooGetDefaultResponse   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/FormatTest.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/FormatTest.java
index 92e3aef3e80d..504fbf6060c3 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/FormatTest.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/FormatTest.java
@@ -330,10 +330,7 @@ public class FormatTest   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
index 50c41f059e3b..4c793c3eeb47 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
@@ -77,10 +77,7 @@ public class HasOnlyReadOnly   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/HealthCheckResult.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/HealthCheckResult.java
index 5b865aa0e3f3..96a10e97b09e 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/HealthCheckResult.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/HealthCheckResult.java
@@ -62,10 +62,7 @@ public class HealthCheckResult   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/MapTest.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/MapTest.java
index f8051c6e3e45..4db323d40fcb 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/MapTest.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/MapTest.java
@@ -151,10 +151,7 @@ public class MapTest   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 9f2e5dc7bbef..b5f6c285a303 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -98,10 +98,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Model200Response.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Model200Response.java
index 28f6bd2cdac0..055d1f78d476 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Model200Response.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Model200Response.java
@@ -79,10 +79,7 @@ public class Model200Response   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ModelApiResponse.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ModelApiResponse.java
index 81a468f1af79..9022022b9544 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ModelApiResponse.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ModelApiResponse.java
@@ -94,10 +94,7 @@ public class ModelApiResponse   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ModelFile.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ModelFile.java
index 6743c641a001..916ce4c96d35 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ModelFile.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ModelFile.java
@@ -62,10 +62,7 @@ public class ModelFile   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ModelList.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ModelList.java
index 88000df9959e..c3aea2a26bf0 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ModelList.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ModelList.java
@@ -60,10 +60,7 @@ public class ModelList   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ModelReturn.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ModelReturn.java
index a11d5e2b4e49..1f53f62880e2 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ModelReturn.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ModelReturn.java
@@ -62,10 +62,7 @@ public class ModelReturn   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Name.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Name.java
index a3524465b284..339cc7be5e5f 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Name.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Name.java
@@ -112,10 +112,7 @@ public class Name   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/NullableClass.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/NullableClass.java
index 11e7e2ec0fd0..b5d03aee1364 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/NullableClass.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/NullableClass.java
@@ -255,10 +255,7 @@ public class NullableClass extends HashMap<String, Object>  {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/NumberOnly.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/NumberOnly.java
index 7caf3c857f39..5de20b5e1f36 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/NumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/NumberOnly.java
@@ -60,10 +60,7 @@ public class NumberOnly   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
index 83bc634c1d6b..fbd3be5598e9 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
@@ -115,10 +115,7 @@ public class ObjectWithDeprecatedFields   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Order.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Order.java
index 0ca5e240f6f6..93886363cfd1 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Order.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Order.java
@@ -185,10 +185,7 @@ public class Order   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/OuterComposite.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/OuterComposite.java
index 696e549642d2..a90c38e4c535 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/OuterComposite.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/OuterComposite.java
@@ -94,10 +94,7 @@ public class OuterComposite   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
index cd57e792975e..8fe2aa89dd61 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
@@ -62,10 +62,7 @@ public class OuterObjectWithEnumProperty   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ParentWithNullable.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ParentWithNullable.java
index e458a6ed3400..af5497566694 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ParentWithNullable.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ParentWithNullable.java
@@ -118,10 +118,7 @@ public class ParentWithNullable   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Pet.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Pet.java
index 671a9be156dc..3ccffcd5b110 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Pet.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Pet.java
@@ -192,10 +192,7 @@ public class Pet   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
index 6e9d1f16fb1d..e2256af87974 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
@@ -76,10 +76,7 @@ public class ReadOnlyFirst   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/SpecialModelName.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/SpecialModelName.java
index 9c14659f899a..6016175f8ff6 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/SpecialModelName.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/SpecialModelName.java
@@ -60,10 +60,7 @@ public class SpecialModelName   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Tag.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Tag.java
index e0d425d782e2..932fe2c5e5e4 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Tag.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/Tag.java
@@ -76,10 +76,7 @@ public class Tag   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 499fa5013feb..3da9bc6713f4 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -62,10 +62,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/User.java b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/User.java
index 9decbea90472..5d1164c694e9 100644
--- a/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/User.java
+++ b/samples/server/petstore/java-helidon-server/v4/se-uac/src/main/java/org/openapitools/server/model/User.java
@@ -178,10 +178,7 @@ public class User   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
index 1266dac5d907..137de19a0591 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/AdditionalPropertiesClass.java
@@ -78,10 +78,7 @@ public class AdditionalPropertiesClass   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
index 63eeb7f67afb..bc9c763d4252 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/AllOfWithSingleRef.java
@@ -79,10 +79,7 @@ public class AllOfWithSingleRef   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Animal.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Animal.java
index 548edc48a8a8..7d9715022a2e 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Animal.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Animal.java
@@ -79,10 +79,7 @@ public class Animal   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
index 83c75a242e8e..ca47a0ebb266 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
@@ -63,10 +63,7 @@ public class ArrayOfArrayOfNumberOnly   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
index 971fb516ba0c..88378ff5947e 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
@@ -63,10 +63,7 @@ public class ArrayOfNumberOnly   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ArrayTest.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ArrayTest.java
index d94cad1da9a3..66bc4141a5b4 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ArrayTest.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ArrayTest.java
@@ -97,10 +97,7 @@ public class ArrayTest   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Capitalization.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Capitalization.java
index 942f62d57fbc..8422bf244c26 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Capitalization.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Capitalization.java
@@ -144,10 +144,7 @@ public class Capitalization   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Cat.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Cat.java
index d0d01e632a5e..b8149dd25f56 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Cat.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Cat.java
@@ -63,10 +63,7 @@ public class Cat extends Animal  {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Category.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Category.java
index ce9f854b3b91..6a506f1786b6 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Category.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Category.java
@@ -76,10 +76,7 @@ public class Category   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ChildWithNullable.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ChildWithNullable.java
index ea4c963b2b56..e3f5db31c840 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ChildWithNullable.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ChildWithNullable.java
@@ -66,10 +66,7 @@ public class ChildWithNullable extends ParentWithNullable  {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ClassModel.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ClassModel.java
index 806a179ba10a..bfe60409c12d 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ClassModel.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ClassModel.java
@@ -61,10 +61,7 @@ public class ClassModel   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Client.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Client.java
index 3b500ac997ee..7b29c5f4dfc7 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Client.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Client.java
@@ -59,10 +59,7 @@ public class Client   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/DeprecatedObject.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/DeprecatedObject.java
index 4e2b7051130c..f4174788bfb8 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/DeprecatedObject.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/DeprecatedObject.java
@@ -59,10 +59,7 @@ public class DeprecatedObject   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Dog.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Dog.java
index f935612575ee..ee9c075dac4c 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Dog.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Dog.java
@@ -63,10 +63,7 @@ public class Dog extends Animal  {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/EnumArrays.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/EnumArrays.java
index 29d6ebaa8fb4..9ea77a9034e7 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/EnumArrays.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/EnumArrays.java
@@ -155,10 +155,7 @@ public class EnumArrays   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/EnumTest.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/EnumTest.java
index d2d7d27c9414..c5158fca9f87 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/EnumTest.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/EnumTest.java
@@ -336,10 +336,7 @@ public class EnumTest   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
index b50b92931cf5..8760e968b923 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/FakeBigDecimalMap200Response.java
@@ -80,10 +80,7 @@ public class FakeBigDecimalMap200Response   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
index 2b6964db9dec..97f7dee2940e 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
@@ -80,10 +80,7 @@ public class FileSchemaTestClass   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Foo.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Foo.java
index e02a00803c22..d006f5faa70b 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Foo.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Foo.java
@@ -59,10 +59,7 @@ public class Foo   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
index 40f8d5855417..df5e23fe5da7 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/FooGetDefaultResponse.java
@@ -61,10 +61,7 @@ public class FooGetDefaultResponse   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/FormatTest.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/FormatTest.java
index 92e3aef3e80d..504fbf6060c3 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/FormatTest.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/FormatTest.java
@@ -330,10 +330,7 @@ public class FormatTest   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
index 50c41f059e3b..4c793c3eeb47 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/HasOnlyReadOnly.java
@@ -77,10 +77,7 @@ public class HasOnlyReadOnly   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/HealthCheckResult.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/HealthCheckResult.java
index 5b865aa0e3f3..96a10e97b09e 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/HealthCheckResult.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/HealthCheckResult.java
@@ -62,10 +62,7 @@ public class HealthCheckResult   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/MapTest.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/MapTest.java
index f8051c6e3e45..4db323d40fcb 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/MapTest.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/MapTest.java
@@ -151,10 +151,7 @@ public class MapTest   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 9f2e5dc7bbef..b5f6c285a303 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -98,10 +98,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Model200Response.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Model200Response.java
index 28f6bd2cdac0..055d1f78d476 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Model200Response.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Model200Response.java
@@ -79,10 +79,7 @@ public class Model200Response   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ModelApiResponse.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ModelApiResponse.java
index 81a468f1af79..9022022b9544 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ModelApiResponse.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ModelApiResponse.java
@@ -94,10 +94,7 @@ public class ModelApiResponse   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ModelFile.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ModelFile.java
index 6743c641a001..916ce4c96d35 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ModelFile.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ModelFile.java
@@ -62,10 +62,7 @@ public class ModelFile   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ModelList.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ModelList.java
index 88000df9959e..c3aea2a26bf0 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ModelList.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ModelList.java
@@ -60,10 +60,7 @@ public class ModelList   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ModelReturn.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ModelReturn.java
index a11d5e2b4e49..1f53f62880e2 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ModelReturn.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ModelReturn.java
@@ -62,10 +62,7 @@ public class ModelReturn   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Name.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Name.java
index a3524465b284..339cc7be5e5f 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Name.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Name.java
@@ -112,10 +112,7 @@ public class Name   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/NullableClass.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/NullableClass.java
index 11e7e2ec0fd0..b5d03aee1364 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/NullableClass.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/NullableClass.java
@@ -255,10 +255,7 @@ public class NullableClass extends HashMap<String, Object>  {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/NumberOnly.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/NumberOnly.java
index 7caf3c857f39..5de20b5e1f36 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/NumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/NumberOnly.java
@@ -60,10 +60,7 @@ public class NumberOnly   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
index 83bc634c1d6b..fbd3be5598e9 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
@@ -115,10 +115,7 @@ public class ObjectWithDeprecatedFields   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Order.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Order.java
index 0ca5e240f6f6..93886363cfd1 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Order.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Order.java
@@ -185,10 +185,7 @@ public class Order   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/OuterComposite.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/OuterComposite.java
index 696e549642d2..a90c38e4c535 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/OuterComposite.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/OuterComposite.java
@@ -94,10 +94,7 @@ public class OuterComposite   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
index cd57e792975e..8fe2aa89dd61 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/OuterObjectWithEnumProperty.java
@@ -62,10 +62,7 @@ public class OuterObjectWithEnumProperty   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ParentWithNullable.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ParentWithNullable.java
index e458a6ed3400..af5497566694 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ParentWithNullable.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ParentWithNullable.java
@@ -118,10 +118,7 @@ public class ParentWithNullable   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Pet.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Pet.java
index 671a9be156dc..3ccffcd5b110 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Pet.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Pet.java
@@ -192,10 +192,7 @@ public class Pet   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
index 6e9d1f16fb1d..e2256af87974 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/ReadOnlyFirst.java
@@ -76,10 +76,7 @@ public class ReadOnlyFirst   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/SpecialModelName.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/SpecialModelName.java
index 9c14659f899a..6016175f8ff6 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/SpecialModelName.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/SpecialModelName.java
@@ -60,10 +60,7 @@ public class SpecialModelName   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Tag.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Tag.java
index e0d425d782e2..932fe2c5e5e4 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Tag.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/Tag.java
@@ -76,10 +76,7 @@ public class Tag   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 499fa5013feb..3da9bc6713f4 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -62,10 +62,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/User.java b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/User.java
index 9decbea90472..5d1164c694e9 100644
--- a/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/User.java
+++ b/samples/server/petstore/java-helidon-server/v4/se/src/main/java/org/openapitools/server/model/User.java
@@ -178,10 +178,7 @@ public class User   {
      * (except the first line).
     */
     private static String toIndentedString(Object o) {
-        if (o == null) {
-          return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 }
 
diff --git a/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/Category.java
index 54f282bff3b1..8d44d2a89398 100644
--- a/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/Category.java
@@ -123,10 +123,7 @@ public class Category {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/ModelApiResponse.java
index fd68d148826f..fde1445ddcaf 100644
--- a/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -152,10 +152,7 @@ public class ModelApiResponse {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/Order.java
index 7ec1875d9bb4..60e67300958b 100644
--- a/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/Order.java
@@ -275,10 +275,7 @@ public class Order {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/Pet.java
index d7b278dd54a5..bd1bdec2d91f 100644
--- a/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/Pet.java
@@ -293,10 +293,7 @@ public class Pet {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/Tag.java
index 16c661c63c2d..7ad28c3431a3 100644
--- a/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/Tag.java
@@ -122,10 +122,7 @@ public class Tag {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/User.java
index baf01bb5556d..13820629cce1 100644
--- a/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/java-micronaut-server/src/main/java/org/openapitools/model/User.java
@@ -296,10 +296,7 @@ public class User {
      * (except the first line).
      */
     private String toIndentedString(Object o) {
-        if (o == null) {
-            return "null";
-        }
-        return o.toString().replace("\n", "\n    ");
+        return o == null ? "null" : o.toString().replace("\n", "\n    ");
     }
 
 }
diff --git a/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/Category.java b/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/Category.java
index 191b8753462a..db3a7f5c9418 100644
--- a/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/Category.java
+++ b/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/Category.java
@@ -128,10 +128,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/ModelApiResponse.java b/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/ModelApiResponse.java
index 68c4246009aa..9f7d47482edb 100644
--- a/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/ModelApiResponse.java
+++ b/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/ModelApiResponse.java
@@ -160,10 +160,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/Order.java b/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/Order.java
index 2e1abf5037aa..325c0823f854 100644
--- a/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/Order.java
+++ b/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/Order.java
@@ -288,10 +288,7 @@ public class Order  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/Pet.java b/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/Pet.java
index 98dbc8599f8a..61c620b18158 100644
--- a/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/Pet.java
+++ b/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/Pet.java
@@ -310,10 +310,7 @@ public class Pet  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/Tag.java b/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/Tag.java
index f38e3decebac..0046386d6b56 100644
--- a/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/Tag.java
+++ b/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/Tag.java
@@ -128,10 +128,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/User.java b/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/User.java
index fdb3b0f6f2f0..50b21d77490f 100644
--- a/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/User.java
+++ b/samples/server/petstore/java-microprofile/src/main/java/org/openapitools/server/model/User.java
@@ -317,10 +317,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index 7a88968134d7..498b832726d9 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -68,10 +68,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
index d0175b2d58dc..72416a89171c 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -69,10 +69,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 4bc586cff91d..0a110c234dc9 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -68,10 +68,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index 0dd3859aa2fc..763c772b53d4 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -363,10 +363,7 @@ public class AdditionalPropertiesClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 6674f51845c5..62f369e9b1f2 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -68,10 +68,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
index 668a25250c48..24511ba20af3 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -69,10 +69,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
index e4747c5e1faa..83de32f95f49 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -68,10 +68,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
index ed055fd30232..27ad2969028c 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -68,10 +68,7 @@ public class AdditionalPropertiesString extends HashMap<String, String>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Animal.java
index 525b92830f26..763b6fb495ea 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Animal.java
@@ -91,10 +91,7 @@ public class Animal   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 8c63397726ce..b4e0d8b02b8c 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -77,10 +77,7 @@ public class ArrayOfArrayOfNumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index 81641f4fb50c..689792d0583e 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -77,10 +77,7 @@ public class ArrayOfNumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayTest.java
index 61c29c9c4374..a98930548924 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -139,10 +139,7 @@ public class ArrayTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/BigCat.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/BigCat.java
index ee63a10c0538..45d082cf0152 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/BigCat.java
@@ -103,10 +103,7 @@ public class BigCat extends Cat  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Capitalization.java
index 78477dbd5bb6..5d0e26a0cd41 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Capitalization.java
@@ -180,10 +180,7 @@ public class Capitalization   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Cat.java
index f89331d25f78..ef79acb03251 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Cat.java
@@ -67,10 +67,7 @@ public class Cat extends Animal  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Category.java
index 6a55dd250109..57bf9d967dae 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Category.java
@@ -88,10 +88,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ClassModel.java
index 8fc0338f7492..bd85d1a1ce56 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ClassModel.java
@@ -66,10 +66,7 @@ public class ClassModel   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Client.java
index d9f84a8f0f83..12d4fd1a3385 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Client.java
@@ -65,10 +65,7 @@ public class Client   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Dog.java
index e306c48df6c5..c7b12d989dc4 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Dog.java
@@ -67,10 +67,7 @@ public class Dog extends Animal  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/EnumArrays.java
index 5a12392cb41c..24b086489709 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -162,10 +162,7 @@ public class EnumArrays   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/EnumTest.java
index 7a1b2632057c..83c77e0beac9 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/EnumTest.java
@@ -288,10 +288,7 @@ public class EnumTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index 375e8dbb6dc4..dd7a3c3cf83f 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -100,10 +100,7 @@ public class FileSchemaTestClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/FormatTest.java
index b39927261449..328fdfda12f6 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/FormatTest.java
@@ -379,10 +379,7 @@ public class FormatTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index 74a84e92f2bb..c770907bf75c 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -71,10 +71,7 @@ public class HasOnlyReadOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/MapTest.java
index 61f15960b3e9..e0acc5665fa5 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/MapTest.java
@@ -200,10 +200,7 @@ public class MapTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index c09952b72ec0..3a1e378ee8e3 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -124,10 +124,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Model200Response.java
index 42d545f26e54..8d00f78d2b75 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Model200Response.java
@@ -90,10 +90,7 @@ public class Model200Response   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ModelApiResponse.java
index 1c46c9ac76e5..5054699ae21a 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -112,10 +112,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ModelFile.java
index a30a51f27dfc..16f09df18498 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ModelFile.java
@@ -67,10 +67,7 @@ public class ModelFile   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ModelList.java
index 93e9fbf56e37..51fa580c363f 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ModelList.java
@@ -66,10 +66,7 @@ public class ModelList   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ModelReturn.java
index b3f2dc2c17bf..271e32c3df94 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -67,10 +67,7 @@ public class ModelReturn   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Name.java
index 0c846fb462a3..20d1eb0ecfcb 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Name.java
@@ -117,10 +117,7 @@ public class Name   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/NumberOnly.java
index bd620e33a6b8..94fa997500a6 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -66,10 +66,7 @@ public class NumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Order.java
index b2fbebeeebc8..48c650639ca5 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Order.java
@@ -215,10 +215,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/OuterComposite.java
index f7efccae8dc5..3df08c0d3c0b 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -112,10 +112,7 @@ public class OuterComposite   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Pet.java
index 8fc3f1f8cc3c..e0b8d4ef43b4 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Pet.java
@@ -236,10 +236,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index 55e8099d1e87..da6ad7f7cd12 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -79,10 +79,7 @@ public class ReadOnlyFirst   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/SpecialModelName.java
index 4629e224bee6..43fe1038073b 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -66,10 +66,7 @@ public class SpecialModelName   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Tag.java
index f28629e83651..7d169ff42348 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Tag.java
@@ -88,10 +88,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/TypeHolderDefault.java
index 2aa2694e4e1d..ba9e32f74c1d 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/TypeHolderDefault.java
@@ -166,10 +166,7 @@ public class TypeHolderDefault   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/TypeHolderExample.java
index e6a0d7e32556..50bf755d4647 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/TypeHolderExample.java
@@ -189,10 +189,7 @@ public class TypeHolderExample   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/User.java
index 5ee182d5c21a..084e20bf36c0 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/User.java
@@ -226,10 +226,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/XmlItem.java
index 714665a9faf7..f316081d734a 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/XmlItem.java
@@ -785,10 +785,7 @@ public class XmlItem   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/Category.java b/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/Category.java
index aa6efc495fee..134d405981f7 100644
--- a/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/Category.java
+++ b/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/Category.java
@@ -90,10 +90,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/ModelApiResponse.java b/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/ModelApiResponse.java
index bdb378941e70..e157bcd33ed3 100644
--- a/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/ModelApiResponse.java
+++ b/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/ModelApiResponse.java
@@ -114,10 +114,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/Order.java b/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/Order.java
index 92ab70896f25..57489c7078ea 100644
--- a/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/Order.java
+++ b/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/Order.java
@@ -217,10 +217,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/Pet.java b/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/Pet.java
index 6ecf9882d8df..db134a38ca36 100644
--- a/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/Pet.java
+++ b/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/Pet.java
@@ -240,10 +240,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/Tag.java b/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/Tag.java
index 0ae133726269..a41c9883d9c1 100644
--- a/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/Tag.java
+++ b/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/Tag.java
@@ -90,10 +90,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/User.java b/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/User.java
index 85c547d85f21..b0c9720caf28 100644
--- a/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/User.java
+++ b/samples/server/petstore/java-play-framework-api-package-override/app/apimodels/User.java
@@ -228,10 +228,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-async/app/apimodels/Category.java b/samples/server/petstore/java-play-framework-async/app/apimodels/Category.java
index aa6efc495fee..134d405981f7 100644
--- a/samples/server/petstore/java-play-framework-async/app/apimodels/Category.java
+++ b/samples/server/petstore/java-play-framework-async/app/apimodels/Category.java
@@ -90,10 +90,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-async/app/apimodels/ModelApiResponse.java b/samples/server/petstore/java-play-framework-async/app/apimodels/ModelApiResponse.java
index bdb378941e70..e157bcd33ed3 100644
--- a/samples/server/petstore/java-play-framework-async/app/apimodels/ModelApiResponse.java
+++ b/samples/server/petstore/java-play-framework-async/app/apimodels/ModelApiResponse.java
@@ -114,10 +114,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-async/app/apimodels/Order.java b/samples/server/petstore/java-play-framework-async/app/apimodels/Order.java
index 92ab70896f25..57489c7078ea 100644
--- a/samples/server/petstore/java-play-framework-async/app/apimodels/Order.java
+++ b/samples/server/petstore/java-play-framework-async/app/apimodels/Order.java
@@ -217,10 +217,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-async/app/apimodels/Pet.java b/samples/server/petstore/java-play-framework-async/app/apimodels/Pet.java
index 6ecf9882d8df..db134a38ca36 100644
--- a/samples/server/petstore/java-play-framework-async/app/apimodels/Pet.java
+++ b/samples/server/petstore/java-play-framework-async/app/apimodels/Pet.java
@@ -240,10 +240,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-async/app/apimodels/Tag.java b/samples/server/petstore/java-play-framework-async/app/apimodels/Tag.java
index 0ae133726269..a41c9883d9c1 100644
--- a/samples/server/petstore/java-play-framework-async/app/apimodels/Tag.java
+++ b/samples/server/petstore/java-play-framework-async/app/apimodels/Tag.java
@@ -90,10 +90,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-async/app/apimodels/User.java b/samples/server/petstore/java-play-framework-async/app/apimodels/User.java
index 85c547d85f21..b0c9720caf28 100644
--- a/samples/server/petstore/java-play-framework-async/app/apimodels/User.java
+++ b/samples/server/petstore/java-play-framework-async/app/apimodels/User.java
@@ -228,10 +228,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-controller-only/app/apimodels/Category.java b/samples/server/petstore/java-play-framework-controller-only/app/apimodels/Category.java
index aa6efc495fee..134d405981f7 100644
--- a/samples/server/petstore/java-play-framework-controller-only/app/apimodels/Category.java
+++ b/samples/server/petstore/java-play-framework-controller-only/app/apimodels/Category.java
@@ -90,10 +90,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-controller-only/app/apimodels/ModelApiResponse.java b/samples/server/petstore/java-play-framework-controller-only/app/apimodels/ModelApiResponse.java
index bdb378941e70..e157bcd33ed3 100644
--- a/samples/server/petstore/java-play-framework-controller-only/app/apimodels/ModelApiResponse.java
+++ b/samples/server/petstore/java-play-framework-controller-only/app/apimodels/ModelApiResponse.java
@@ -114,10 +114,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-controller-only/app/apimodels/Order.java b/samples/server/petstore/java-play-framework-controller-only/app/apimodels/Order.java
index 92ab70896f25..57489c7078ea 100644
--- a/samples/server/petstore/java-play-framework-controller-only/app/apimodels/Order.java
+++ b/samples/server/petstore/java-play-framework-controller-only/app/apimodels/Order.java
@@ -217,10 +217,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-controller-only/app/apimodels/Pet.java b/samples/server/petstore/java-play-framework-controller-only/app/apimodels/Pet.java
index 6ecf9882d8df..db134a38ca36 100644
--- a/samples/server/petstore/java-play-framework-controller-only/app/apimodels/Pet.java
+++ b/samples/server/petstore/java-play-framework-controller-only/app/apimodels/Pet.java
@@ -240,10 +240,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-controller-only/app/apimodels/Tag.java b/samples/server/petstore/java-play-framework-controller-only/app/apimodels/Tag.java
index 0ae133726269..a41c9883d9c1 100644
--- a/samples/server/petstore/java-play-framework-controller-only/app/apimodels/Tag.java
+++ b/samples/server/petstore/java-play-framework-controller-only/app/apimodels/Tag.java
@@ -90,10 +90,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-controller-only/app/apimodels/User.java b/samples/server/petstore/java-play-framework-controller-only/app/apimodels/User.java
index 85c547d85f21..b0c9720caf28 100644
--- a/samples/server/petstore/java-play-framework-controller-only/app/apimodels/User.java
+++ b/samples/server/petstore/java-play-framework-controller-only/app/apimodels/User.java
@@ -228,10 +228,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/Category.java b/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/Category.java
index aa6efc495fee..134d405981f7 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/Category.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/Category.java
@@ -90,10 +90,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/ModelApiResponse.java b/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/ModelApiResponse.java
index bdb378941e70..e157bcd33ed3 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/ModelApiResponse.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/ModelApiResponse.java
@@ -114,10 +114,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/Order.java b/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/Order.java
index 92ab70896f25..57489c7078ea 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/Order.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/Order.java
@@ -217,10 +217,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/Pet.java b/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/Pet.java
index 6ecf9882d8df..db134a38ca36 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/Pet.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/Pet.java
@@ -240,10 +240,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/Tag.java b/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/Tag.java
index 0ae133726269..a41c9883d9c1 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/Tag.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/Tag.java
@@ -90,10 +90,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/User.java b/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/User.java
index 85c547d85f21..b0c9720caf28 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/User.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints-with-security/app/apimodels/User.java
@@ -228,10 +228,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesAnyType.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesAnyType.java
index b57bed702f5a..ac0e4f66c6f3 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesAnyType.java
@@ -70,10 +70,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesArray.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesArray.java
index 8d63dd1eea55..351900302d21 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesArray.java
@@ -71,10 +71,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesBoolean.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesBoolean.java
index a4d090de69d9..27b337347aef 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesBoolean.java
@@ -70,10 +70,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesClass.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesClass.java
index 858feb8ddaba..5fce9caf5aea 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesClass.java
@@ -370,10 +370,7 @@ public class AdditionalPropertiesClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesInteger.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesInteger.java
index 755990ec884c..8b39c7043d43 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesInteger.java
@@ -70,10 +70,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesNumber.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesNumber.java
index 3747f772e3b7..a4db2a58ef5c 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesNumber.java
@@ -71,10 +71,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesObject.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesObject.java
index 09a64d631d26..85982ad9aa59 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesObject.java
@@ -70,10 +70,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesString.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesString.java
index 927edff3f000..35a322ea3ade 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesString.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/AdditionalPropertiesString.java
@@ -70,10 +70,7 @@ public class AdditionalPropertiesString extends HashMap<String, String>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Animal.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Animal.java
index e310b42c032e..2aa9d4e295ac 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Animal.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Animal.java
@@ -94,10 +94,7 @@ public class Animal   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ArrayOfArrayOfNumberOnly.java
index 19b9e502f5d4..60c9ec318a36 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ArrayOfArrayOfNumberOnly.java
@@ -80,10 +80,7 @@ public class ArrayOfArrayOfNumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ArrayOfNumberOnly.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ArrayOfNumberOnly.java
index bf257402557d..8b55817acb64 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ArrayOfNumberOnly.java
@@ -80,10 +80,7 @@ public class ArrayOfNumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ArrayTest.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ArrayTest.java
index 6a3993842eed..972d0f182ddf 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ArrayTest.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ArrayTest.java
@@ -143,10 +143,7 @@ public class ArrayTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/BigCat.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/BigCat.java
index 4a0a7479a97c..c221e036a57f 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/BigCat.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/BigCat.java
@@ -104,10 +104,7 @@ public class BigCat extends Cat  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Capitalization.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Capitalization.java
index 721dbb32a8b7..551712434422 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Capitalization.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Capitalization.java
@@ -182,10 +182,7 @@ public class Capitalization   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Cat.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Cat.java
index ad3360830c66..d00db19bef20 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Cat.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Cat.java
@@ -69,10 +69,7 @@ public class Cat extends Animal  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Category.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Category.java
index e70988e5a528..fe7cfeaaf1d2 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Category.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Category.java
@@ -91,10 +91,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ClassModel.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ClassModel.java
index c7fdb77197a1..07c3f3eb22da 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ClassModel.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ClassModel.java
@@ -67,10 +67,7 @@ public class ClassModel   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Client.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Client.java
index 062c53c7ecdb..3079ded8dba6 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Client.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Client.java
@@ -67,10 +67,7 @@ public class Client   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Dog.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Dog.java
index 097761f3bc19..bc403b8f1462 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Dog.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Dog.java
@@ -69,10 +69,7 @@ public class Dog extends Animal  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/EnumArrays.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/EnumArrays.java
index 7559146b28f4..f453166adcb3 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/EnumArrays.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/EnumArrays.java
@@ -163,10 +163,7 @@ public class EnumArrays   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/EnumTest.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/EnumTest.java
index 75954acb09d1..8fc0e77635ff 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/EnumTest.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/EnumTest.java
@@ -291,10 +291,7 @@ public class EnumTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/FileSchemaTestClass.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/FileSchemaTestClass.java
index c200d4f0eb66..ca55e50447bf 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/FileSchemaTestClass.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/FileSchemaTestClass.java
@@ -104,10 +104,7 @@ public class FileSchemaTestClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/FormatTest.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/FormatTest.java
index 24524c9b7de6..c300704a57ee 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/FormatTest.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/FormatTest.java
@@ -405,10 +405,7 @@ public class FormatTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/HasOnlyReadOnly.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/HasOnlyReadOnly.java
index 43125b45dd92..54013dafaf45 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/HasOnlyReadOnly.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/HasOnlyReadOnly.java
@@ -91,10 +91,7 @@ public class HasOnlyReadOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/MapTest.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/MapTest.java
index e9744dd39c87..ba2ccfb4606d 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/MapTest.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/MapTest.java
@@ -202,10 +202,7 @@ public class MapTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/MixedPropertiesAndAdditionalPropertiesClass.java
index b0446a33a625..b959ca2fe488 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -129,10 +129,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Model200Response.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Model200Response.java
index 94efc47b2fba..60b6b5c6b4a8 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Model200Response.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Model200Response.java
@@ -91,10 +91,7 @@ public class Model200Response   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ModelApiResponse.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ModelApiResponse.java
index 8bf633f5c952..f41a6d70ebb8 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ModelApiResponse.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ModelApiResponse.java
@@ -114,10 +114,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ModelFile.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ModelFile.java
index e914c3326fbb..ceb617e2b19d 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ModelFile.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ModelFile.java
@@ -68,10 +68,7 @@ public class ModelFile   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ModelList.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ModelList.java
index 528b68d9cbfe..4f8a772b60f6 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ModelList.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ModelList.java
@@ -68,10 +68,7 @@ public class ModelList   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ModelReturn.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ModelReturn.java
index da72c7b5d996..631d8d9d3c33 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ModelReturn.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ModelReturn.java
@@ -68,10 +68,7 @@ public class ModelReturn   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Name.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Name.java
index dc0b1f1abfd7..530576c78327 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Name.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Name.java
@@ -137,10 +137,7 @@ public class Name   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/NumberOnly.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/NumberOnly.java
index 8ca6dd09d988..3c8de22a2355 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/NumberOnly.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/NumberOnly.java
@@ -69,10 +69,7 @@ public class NumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Order.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Order.java
index faa7157a9b62..1b146488b826 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Order.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Order.java
@@ -217,10 +217,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/OuterComposite.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/OuterComposite.java
index 1307b8341257..4c18e76054d1 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/OuterComposite.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/OuterComposite.java
@@ -115,10 +115,7 @@ public class OuterComposite   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Pet.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Pet.java
index 2b7bda970aec..e0fb460f3141 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Pet.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Pet.java
@@ -244,10 +244,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ReadOnlyFirst.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ReadOnlyFirst.java
index 4be646b1611f..94f32de67a53 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ReadOnlyFirst.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/ReadOnlyFirst.java
@@ -90,10 +90,7 @@ public class ReadOnlyFirst   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/SpecialModelName.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/SpecialModelName.java
index baa153ee7ebb..d506a3489091 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/SpecialModelName.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/SpecialModelName.java
@@ -68,10 +68,7 @@ public class SpecialModelName   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Tag.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Tag.java
index 4a4c657b07cc..ac1e751f60cb 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Tag.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/Tag.java
@@ -90,10 +90,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/TypeHolderDefault.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/TypeHolderDefault.java
index 67c9e0848ed2..52d0b6444ac8 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/TypeHolderDefault.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/TypeHolderDefault.java
@@ -177,10 +177,7 @@ public class TypeHolderDefault   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/TypeHolderExample.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/TypeHolderExample.java
index 56d2fc7dae8f..2b9a22f6d2bc 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/TypeHolderExample.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/TypeHolderExample.java
@@ -201,10 +201,7 @@ public class TypeHolderExample   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/User.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/User.java
index 5325f8cce387..e005a65f96df 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/User.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/User.java
@@ -228,10 +228,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/XmlItem.java b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/XmlItem.java
index 3158c86b334b..509d5987047d 100644
--- a/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/XmlItem.java
+++ b/samples/server/petstore/java-play-framework-fake-endpoints/app/apimodels/XmlItem.java
@@ -792,10 +792,7 @@ public class XmlItem   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/Category.java b/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/Category.java
index 5be3c7114b95..93666c691202 100644
--- a/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/Category.java
+++ b/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/Category.java
@@ -86,10 +86,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/ModelApiResponse.java b/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/ModelApiResponse.java
index 612852dbf92b..73698ff0cdc5 100644
--- a/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/ModelApiResponse.java
+++ b/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/ModelApiResponse.java
@@ -109,10 +109,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/Order.java b/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/Order.java
index 9e5ceaed80ba..1354d54a038f 100644
--- a/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/Order.java
+++ b/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/Order.java
@@ -208,10 +208,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/Pet.java b/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/Pet.java
index 318cb67c8894..a294bde7630a 100644
--- a/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/Pet.java
+++ b/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/Pet.java
@@ -228,10 +228,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/Tag.java b/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/Tag.java
index c977e725ef2e..d05b3fc9f9ff 100644
--- a/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/Tag.java
+++ b/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/Tag.java
@@ -86,10 +86,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/User.java b/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/User.java
index 4316f5cd81d3..5c6bfb00ebe9 100644
--- a/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/User.java
+++ b/samples/server/petstore/java-play-framework-no-bean-validation/app/apimodels/User.java
@@ -218,10 +218,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/Category.java b/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/Category.java
index aa6efc495fee..134d405981f7 100644
--- a/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/Category.java
+++ b/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/Category.java
@@ -90,10 +90,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/ModelApiResponse.java b/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/ModelApiResponse.java
index bdb378941e70..e157bcd33ed3 100644
--- a/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/ModelApiResponse.java
+++ b/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/ModelApiResponse.java
@@ -114,10 +114,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/Order.java b/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/Order.java
index 92ab70896f25..57489c7078ea 100644
--- a/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/Order.java
+++ b/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/Order.java
@@ -217,10 +217,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/Pet.java b/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/Pet.java
index 6ecf9882d8df..db134a38ca36 100644
--- a/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/Pet.java
+++ b/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/Pet.java
@@ -240,10 +240,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/Tag.java b/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/Tag.java
index 0ae133726269..a41c9883d9c1 100644
--- a/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/Tag.java
+++ b/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/Tag.java
@@ -90,10 +90,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/User.java b/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/User.java
index 85c547d85f21..b0c9720caf28 100644
--- a/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/User.java
+++ b/samples/server/petstore/java-play-framework-no-excp-handling/app/apimodels/User.java
@@ -228,10 +228,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-interface/app/apimodels/Category.java b/samples/server/petstore/java-play-framework-no-interface/app/apimodels/Category.java
index aa6efc495fee..134d405981f7 100644
--- a/samples/server/petstore/java-play-framework-no-interface/app/apimodels/Category.java
+++ b/samples/server/petstore/java-play-framework-no-interface/app/apimodels/Category.java
@@ -90,10 +90,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-interface/app/apimodels/ModelApiResponse.java b/samples/server/petstore/java-play-framework-no-interface/app/apimodels/ModelApiResponse.java
index bdb378941e70..e157bcd33ed3 100644
--- a/samples/server/petstore/java-play-framework-no-interface/app/apimodels/ModelApiResponse.java
+++ b/samples/server/petstore/java-play-framework-no-interface/app/apimodels/ModelApiResponse.java
@@ -114,10 +114,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-interface/app/apimodels/Order.java b/samples/server/petstore/java-play-framework-no-interface/app/apimodels/Order.java
index 92ab70896f25..57489c7078ea 100644
--- a/samples/server/petstore/java-play-framework-no-interface/app/apimodels/Order.java
+++ b/samples/server/petstore/java-play-framework-no-interface/app/apimodels/Order.java
@@ -217,10 +217,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-interface/app/apimodels/Pet.java b/samples/server/petstore/java-play-framework-no-interface/app/apimodels/Pet.java
index 6ecf9882d8df..db134a38ca36 100644
--- a/samples/server/petstore/java-play-framework-no-interface/app/apimodels/Pet.java
+++ b/samples/server/petstore/java-play-framework-no-interface/app/apimodels/Pet.java
@@ -240,10 +240,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-interface/app/apimodels/Tag.java b/samples/server/petstore/java-play-framework-no-interface/app/apimodels/Tag.java
index 0ae133726269..a41c9883d9c1 100644
--- a/samples/server/petstore/java-play-framework-no-interface/app/apimodels/Tag.java
+++ b/samples/server/petstore/java-play-framework-no-interface/app/apimodels/Tag.java
@@ -90,10 +90,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-interface/app/apimodels/User.java b/samples/server/petstore/java-play-framework-no-interface/app/apimodels/User.java
index 85c547d85f21..b0c9720caf28 100644
--- a/samples/server/petstore/java-play-framework-no-interface/app/apimodels/User.java
+++ b/samples/server/petstore/java-play-framework-no-interface/app/apimodels/User.java
@@ -228,10 +228,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/Category.java b/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/Category.java
index aa6efc495fee..134d405981f7 100644
--- a/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/Category.java
+++ b/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/Category.java
@@ -90,10 +90,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/ModelApiResponse.java b/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/ModelApiResponse.java
index bdb378941e70..e157bcd33ed3 100644
--- a/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/ModelApiResponse.java
+++ b/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/ModelApiResponse.java
@@ -114,10 +114,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/Order.java b/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/Order.java
index 92ab70896f25..57489c7078ea 100644
--- a/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/Order.java
+++ b/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/Order.java
@@ -217,10 +217,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/Pet.java b/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/Pet.java
index 6ecf9882d8df..db134a38ca36 100644
--- a/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/Pet.java
+++ b/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/Pet.java
@@ -240,10 +240,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/Tag.java b/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/Tag.java
index 0ae133726269..a41c9883d9c1 100644
--- a/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/Tag.java
+++ b/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/Tag.java
@@ -90,10 +90,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/User.java b/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/User.java
index 85c547d85f21..b0c9720caf28 100644
--- a/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/User.java
+++ b/samples/server/petstore/java-play-framework-no-nullable/app/apimodels/User.java
@@ -228,10 +228,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/Category.java b/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/Category.java
index aa6efc495fee..134d405981f7 100644
--- a/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/Category.java
+++ b/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/Category.java
@@ -90,10 +90,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/ModelApiResponse.java b/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/ModelApiResponse.java
index bdb378941e70..e157bcd33ed3 100644
--- a/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/ModelApiResponse.java
+++ b/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/ModelApiResponse.java
@@ -114,10 +114,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/Order.java b/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/Order.java
index 92ab70896f25..57489c7078ea 100644
--- a/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/Order.java
+++ b/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/Order.java
@@ -217,10 +217,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/Pet.java b/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/Pet.java
index 6ecf9882d8df..db134a38ca36 100644
--- a/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/Pet.java
+++ b/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/Pet.java
@@ -240,10 +240,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/Tag.java b/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/Tag.java
index 0ae133726269..a41c9883d9c1 100644
--- a/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/Tag.java
+++ b/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/Tag.java
@@ -90,10 +90,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/User.java b/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/User.java
index 85c547d85f21..b0c9720caf28 100644
--- a/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/User.java
+++ b/samples/server/petstore/java-play-framework-no-swagger-ui/app/apimodels/User.java
@@ -228,10 +228,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/Category.java b/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/Category.java
index aa6efc495fee..134d405981f7 100644
--- a/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/Category.java
+++ b/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/Category.java
@@ -90,10 +90,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/ModelApiResponse.java b/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/ModelApiResponse.java
index bdb378941e70..e157bcd33ed3 100644
--- a/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/ModelApiResponse.java
+++ b/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/ModelApiResponse.java
@@ -114,10 +114,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/Order.java b/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/Order.java
index 92ab70896f25..57489c7078ea 100644
--- a/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/Order.java
+++ b/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/Order.java
@@ -217,10 +217,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/Pet.java b/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/Pet.java
index 6ecf9882d8df..db134a38ca36 100644
--- a/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/Pet.java
+++ b/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/Pet.java
@@ -240,10 +240,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/Tag.java b/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/Tag.java
index 0ae133726269..a41c9883d9c1 100644
--- a/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/Tag.java
+++ b/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/Tag.java
@@ -90,10 +90,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/User.java b/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/User.java
index 85c547d85f21..b0c9720caf28 100644
--- a/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/User.java
+++ b/samples/server/petstore/java-play-framework-no-wrap-calls/app/apimodels/User.java
@@ -228,10 +228,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework/app/apimodels/Category.java b/samples/server/petstore/java-play-framework/app/apimodels/Category.java
index aa6efc495fee..134d405981f7 100644
--- a/samples/server/petstore/java-play-framework/app/apimodels/Category.java
+++ b/samples/server/petstore/java-play-framework/app/apimodels/Category.java
@@ -90,10 +90,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework/app/apimodels/ModelApiResponse.java b/samples/server/petstore/java-play-framework/app/apimodels/ModelApiResponse.java
index bdb378941e70..e157bcd33ed3 100644
--- a/samples/server/petstore/java-play-framework/app/apimodels/ModelApiResponse.java
+++ b/samples/server/petstore/java-play-framework/app/apimodels/ModelApiResponse.java
@@ -114,10 +114,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework/app/apimodels/Order.java b/samples/server/petstore/java-play-framework/app/apimodels/Order.java
index 92ab70896f25..57489c7078ea 100644
--- a/samples/server/petstore/java-play-framework/app/apimodels/Order.java
+++ b/samples/server/petstore/java-play-framework/app/apimodels/Order.java
@@ -217,10 +217,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework/app/apimodels/Pet.java b/samples/server/petstore/java-play-framework/app/apimodels/Pet.java
index 6ecf9882d8df..db134a38ca36 100644
--- a/samples/server/petstore/java-play-framework/app/apimodels/Pet.java
+++ b/samples/server/petstore/java-play-framework/app/apimodels/Pet.java
@@ -240,10 +240,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework/app/apimodels/Tag.java b/samples/server/petstore/java-play-framework/app/apimodels/Tag.java
index 0ae133726269..a41c9883d9c1 100644
--- a/samples/server/petstore/java-play-framework/app/apimodels/Tag.java
+++ b/samples/server/petstore/java-play-framework/app/apimodels/Tag.java
@@ -90,10 +90,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-play-framework/app/apimodels/User.java b/samples/server/petstore/java-play-framework/app/apimodels/User.java
index 85c547d85f21..b0c9720caf28 100644
--- a/samples/server/petstore/java-play-framework/app/apimodels/User.java
+++ b/samples/server/petstore/java-play-framework/app/apimodels/User.java
@@ -228,10 +228,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Category.java
index 3e5cfb81da53..fde18412341f 100644
--- a/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Category.java
@@ -98,10 +98,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/ModelApiResponse.java
index cc5c3e3826ea..949c39fad89e 100644
--- a/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -118,10 +118,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Order.java
index ab756a90e68a..6011ae54f6e0 100644
--- a/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Order.java
@@ -201,10 +201,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Pet.java
index ebea83d4d148..8c095717b4e7 100644
--- a/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Pet.java
@@ -205,10 +205,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Tag.java
index dae986f4d8aa..e5f4b6d99e27 100644
--- a/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Tag.java
@@ -98,10 +98,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/User.java
index 3f3750e428eb..2ff0cc673fa8 100644
--- a/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/User.java
@@ -219,10 +219,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Category.java b/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Category.java
index 992be98373dc..3c72d58af212 100644
--- a/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Category.java
+++ b/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Category.java
@@ -75,9 +75,6 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/ModelApiResponse.java b/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/ModelApiResponse.java
index 9c7fa0e9af3f..d1ca04dd7061 100644
--- a/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/ModelApiResponse.java
+++ b/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/ModelApiResponse.java
@@ -88,9 +88,6 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Order.java b/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Order.java
index 24c854f5948a..74185a950f2e 100644
--- a/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Order.java
+++ b/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Order.java
@@ -149,9 +149,6 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Pet.java b/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Pet.java
index 7aae8f77aaad..02db025385b4 100644
--- a/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Pet.java
+++ b/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Pet.java
@@ -153,9 +153,6 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Tag.java b/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Tag.java
index bad53e0107e7..8c8fdbd1bda0 100644
--- a/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Tag.java
+++ b/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Tag.java
@@ -75,9 +75,6 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/User.java b/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/User.java
index 989b3bca5568..0d62571820ed 100644
--- a/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/User.java
+++ b/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/User.java
@@ -153,9 +153,6 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
diff --git a/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/Category.java
index c366f40681d8..2a21951f0188 100644
--- a/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/Category.java
@@ -92,10 +92,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/ModelApiResponse.java
index ebf9005823f3..8b1a9cf163a5 100644
--- a/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -117,10 +117,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/Order.java
index a4a5ba29a53c..1e9038ab5e8f 100644
--- a/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/Order.java
@@ -229,10 +229,7 @@ PLACED(String.valueOf("placed")), APPROVED(String.valueOf("approved")), DELIVERE
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/Pet.java
index 92a63897d073..14f3a22e91fc 100644
--- a/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/Pet.java
@@ -249,10 +249,7 @@ AVAILABLE(String.valueOf("available")), PENDING(String.valueOf("pending")), SOLD
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/Tag.java
index e7ef41df3e53..490f4ba48ef9 100644
--- a/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/Tag.java
@@ -92,10 +92,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/User.java
index 7475969c2f28..9426c33cf236 100644
--- a/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-cxf-annotated-base-path/src/gen/java/org/openapitools/model/User.java
@@ -239,10 +239,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/Category.java
index a1177cbf5c9d..56970bd11567 100644
--- a/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/Category.java
@@ -93,10 +93,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/ModelApiResponse.java
index ab73f11f8e8a..a60a3828add6 100644
--- a/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -116,10 +116,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/Order.java
index db304e3912fe..e642f3865d0b 100644
--- a/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/Order.java
@@ -213,10 +213,7 @@ public enum StatusEnum {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/Pet.java
index 1313d9b3b36d..ca19fc36aab3 100644
--- a/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/Pet.java
@@ -236,10 +236,7 @@ public enum StatusEnum {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/Tag.java
index 62cb384efea7..7e9ac715d989 100644
--- a/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/Tag.java
@@ -93,10 +93,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/User.java
index 8c95fc5ddd94..b230b2e5651d 100644
--- a/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-cxf-cdi/src/gen/java/org/openapitools/model/User.java
@@ -226,10 +226,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/Category.java
index c366f40681d8..2a21951f0188 100644
--- a/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/Category.java
@@ -92,10 +92,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/ModelApiResponse.java
index ebf9005823f3..8b1a9cf163a5 100644
--- a/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -117,10 +117,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/Order.java
index a4a5ba29a53c..1e9038ab5e8f 100644
--- a/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/Order.java
@@ -229,10 +229,7 @@ PLACED(String.valueOf("placed")), APPROVED(String.valueOf("approved")), DELIVERE
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/Pet.java
index 92a63897d073..14f3a22e91fc 100644
--- a/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/Pet.java
@@ -249,10 +249,7 @@ AVAILABLE(String.valueOf("available")), PENDING(String.valueOf("pending")), SOLD
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/Tag.java
index e7ef41df3e53..490f4ba48ef9 100644
--- a/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/Tag.java
@@ -92,10 +92,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/User.java
index 7475969c2f28..9426c33cf236 100644
--- a/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-cxf-non-spring-app/src/gen/java/org/openapitools/model/User.java
@@ -239,10 +239,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index d502d49462c4..642f9c0e72bf 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -66,10 +66,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object> {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
index b970ecd72ded..02e793029312 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -67,10 +67,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List> {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 36815cbe6884..0e362a2cf3e1 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -66,10 +66,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean> {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index 25a78f360b64..67fe33ebafd7 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -357,10 +357,7 @@ public class AdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
index f03f9b02b870..35bf1412cf1f 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -66,10 +66,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer> {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
index 447f016c5562..e3b6c87939d3 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -67,10 +67,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal> {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
index 1d474b228645..bd090cbbcfc7 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -66,10 +66,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map> {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
index 1f9d1fab755e..973a94e42a1f 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -66,10 +66,7 @@ public class AdditionalPropertiesString extends HashMap<String, String> {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Animal.java
index df698533b477..8b72fb26426b 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Animal.java
@@ -97,10 +97,7 @@ public class Animal  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 77756b4a7334..b6898cbc5132 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -74,10 +74,7 @@ public class ArrayOfArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index d0fa39a28d0e..883cc638189c 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -74,10 +74,7 @@ public class ArrayOfNumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ArrayTest.java
index 79056c510967..fbc2e7a24bd7 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -134,10 +134,7 @@ public class ArrayTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/BigCat.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/BigCat.java
index f089bc64dbb4..15d4bcf4c0ba 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/BigCat.java
@@ -102,10 +102,7 @@ LIONS(String.valueOf("lions")), TIGERS(String.valueOf("tigers")), LEOPARDS(Strin
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Capitalization.java
index 68c92bc6b89f..bb8ac6fe8bc2 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Capitalization.java
@@ -186,10 +186,7 @@ public class Capitalization  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Cat.java
index 84a4f7177306..e49feaf45c08 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Cat.java
@@ -65,10 +65,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Category.java
index 7af9db7265ea..71b517e526f5 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Category.java
@@ -88,10 +88,7 @@ public class Category  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ClassModel.java
index bde081295bd6..ee39aacb0339 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ClassModel.java
@@ -68,10 +68,7 @@ public class ClassModel  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Client.java
index 2c09cb21b3f5..aa6d7fd81db1 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Client.java
@@ -63,10 +63,7 @@ public class Client  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Dog.java
index c92d97ba2962..5a26cc2c150a 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Dog.java
@@ -65,10 +65,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/EnumArrays.java
index c61c51b294b1..ccc9f3ce1bd5 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -164,10 +164,7 @@ FISH(String.valueOf("fish")), CRAB(String.valueOf("crab"));
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/EnumTest.java
index 70aba52508c3..a810d34e8388 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/EnumTest.java
@@ -306,10 +306,7 @@ NUMBER_1_DOT_1(Double.valueOf(1.1)), NUMBER_MINUS_1_DOT_2(Double.valueOf(-1.2));
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index 27b3c7b091ff..b2b151ec800f 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -100,10 +100,7 @@ public class FileSchemaTestClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/FormatTest.java
index f45cfce39fbb..065cbaf3dcfe 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/FormatTest.java
@@ -399,10 +399,7 @@ public class FormatTest  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index ca06a2b7f003..bf2010be62ec 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -72,10 +72,7 @@ public class HasOnlyReadOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/MapTest.java
index 3b5413bd100e..7cb3f921f3b6 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/MapTest.java
@@ -193,10 +193,7 @@ UPPER(String.valueOf("UPPER")), LOWER(String.valueOf("lower"));
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 297fa8c86a22..e4d74c1d6e32 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -123,10 +123,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Model200Response.java
index 4461f378a4a5..acca81664126 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Model200Response.java
@@ -93,10 +93,7 @@ public class Model200Response  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ModelApiResponse.java
index 13e0ee26e931..cecc972802ef 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -112,10 +112,7 @@ public class ModelApiResponse  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ModelFile.java
index ebeb6e0e6f48..9ee15ef27ee0 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ModelFile.java
@@ -72,10 +72,7 @@ public class ModelFile  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ModelList.java
index 4cb22ef9858c..6f96a504280a 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ModelList.java
@@ -64,10 +64,7 @@ public class ModelList  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ModelReturn.java
index 7be3c8ef1c99..2c22a8fbe86a 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -69,10 +69,7 @@ public class ModelReturn  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Name.java
index fc9394f7ff7f..51439820045f 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Name.java
@@ -125,10 +125,7 @@ public class Name  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/NumberOnly.java
index 780fdfd57fb6..a6d8604eabd1 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -66,10 +66,7 @@ public class NumberOnly  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Order.java
index 0d4f8f8f4045..abc3723c64f1 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Order.java
@@ -224,10 +224,7 @@ PLACED(String.valueOf("placed")), APPROVED(String.valueOf("approved")), DELIVERE
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/OuterComposite.java
index 43eb7d920d68..05307ac98730 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -114,10 +114,7 @@ public class OuterComposite  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Pet.java
index 86333a20ca76..b2f457534704 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Pet.java
@@ -248,10 +248,7 @@ AVAILABLE(String.valueOf("available")), PENDING(String.valueOf("pending")), SOLD
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index b04aadde51ef..6e67bc89df9f 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -79,10 +79,7 @@ public class ReadOnlyFirst  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/SpecialModelName.java
index aab10cc98ce9..0501a5fefc1c 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -64,10 +64,7 @@ public class SpecialModelName  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Tag.java
index 7675b17cd4c5..603f2a95aa8f 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/Tag.java
@@ -87,10 +87,7 @@ public class Tag  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/TypeHolderDefault.java
index 33d455e2af2e..4ed4e2451883 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/TypeHolderDefault.java
@@ -175,10 +175,7 @@ public class TypeHolderDefault  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/TypeHolderExample.java
index e32345c8d7da..130a6b85432e 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/TypeHolderExample.java
@@ -200,10 +200,7 @@ public class TypeHolderExample  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/User.java
index 30371dbe56c7..7f34de8bff8e 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/User.java
@@ -234,10 +234,7 @@ public class User  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/XmlItem.java
index f3e1c4c7ce0f..c6df3b11097f 100644
--- a/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/jaxrs-cxf/src/gen/java/org/openapitools/model/XmlItem.java
@@ -794,10 +794,7 @@ public class XmlItem  {
    * (except the first line).
    */
   private static String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index d0f0e2523b95..f5be78e4c1b9 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -90,10 +90,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object> impleme
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
index 209f49836b3a..69cabd5d52ac 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -91,10 +91,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List> implements
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index d92a54809ca9..76d2a28827a3 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -90,10 +90,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean> implem
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index 3a86f271176c..684a92cbae47 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -426,10 +426,7 @@ public class AdditionalPropertiesClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
index f5bc51a5b1f0..36b776e43113 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -90,10 +90,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer> implem
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
index 058576c0d40f..7c8232ae07c4 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -91,10 +91,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal> impl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
index f5af8010410f..92ee7ce6faf6 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -90,10 +90,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map> implements
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
index 8035a3cc044c..9182c22013a9 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -90,10 +90,7 @@ public class AdditionalPropertiesString extends HashMap<String, String> implemen
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Animal.java
index c6d01ac81015..bbd44aa7d621 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Animal.java
@@ -124,10 +124,7 @@ public class Animal  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 08d64f187bad..7de9eb4a91f5 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -100,10 +100,7 @@ public class ArrayOfArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index adf9e88e8524..0a1a3701b927 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -100,10 +100,7 @@ public class ArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ArrayTest.java
index d4a4e94d2a52..73f3ac00bff4 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -170,10 +170,7 @@ public class ArrayTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/BigCat.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/BigCat.java
index 30ee4856ba1c..6eebbf42407a 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/BigCat.java
@@ -129,10 +129,7 @@ public class BigCat extends Cat implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Capitalization.java
index 0170376fd719..edb19efd2f97 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Capitalization.java
@@ -223,10 +223,7 @@ public class Capitalization  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Cat.java
index 80902e4f3faf..a73a6245e27c 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Cat.java
@@ -89,10 +89,7 @@ public class Cat extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Category.java
index 11a7c86eb81f..b3fc8275015d 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Category.java
@@ -115,10 +115,7 @@ public class Category  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ClassModel.java
index c9972062ccd3..31f330face8f 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ClassModel.java
@@ -89,10 +89,7 @@ public class ClassModel  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Client.java
index 99afe243ad93..d53fe5e6869b 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Client.java
@@ -88,10 +88,7 @@ public class Client  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Dog.java
index 430e5f4ab33b..fe02c224f37d 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Dog.java
@@ -89,10 +89,7 @@ public class Dog extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/EnumArrays.java
index 7aa8fe6f2216..83e06f13ff0b 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -197,10 +197,7 @@ public class EnumArrays  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/EnumTest.java
index c86235639800..592f2cf82cfd 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/EnumTest.java
@@ -343,10 +343,7 @@ public class EnumTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index 377e8ce41639..294bcb17f529 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -127,10 +127,7 @@ public class FileSchemaTestClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/FormatTest.java
index bb4233b9d220..622adfb804a9 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/FormatTest.java
@@ -455,10 +455,7 @@ public class FormatTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index e50d11d441bb..8aff2d8f0083 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -116,10 +116,7 @@ public class HasOnlyReadOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/MapTest.java
index 887cfe708ce4..4852e7a8d6f8 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/MapTest.java
@@ -239,10 +239,7 @@ public class MapTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index f665381b4172..d9a013615c84 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -155,10 +155,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Model200Response.java
index 1d919042cc14..cb3a9aae3887 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Model200Response.java
@@ -117,10 +117,7 @@ public class Model200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ModelApiResponse.java
index ecd16a64a0fa..3d3d6f505bb1 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -143,10 +143,7 @@ public class ModelApiResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ModelFile.java
index c2a4f087f851..1ba104bc36bc 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ModelFile.java
@@ -90,10 +90,7 @@ public class ModelFile  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ModelList.java
index d23aa4029441..818fd8bf5866 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ModelList.java
@@ -89,10 +89,7 @@ public class ModelList  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ModelReturn.java
index 689244759bde..f73ccecd33ab 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -90,10 +90,7 @@ public class ModelReturn  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Name.java
index 755a7abe11d4..35739fe64d85 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Name.java
@@ -170,10 +170,7 @@ public class Name  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/NumberOnly.java
index 21069080d812..5d522443ed79 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -89,10 +89,7 @@ public class NumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Order.java
index 01ae89651e96..6cf2b370aa32 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Order.java
@@ -262,10 +262,7 @@ public class Order  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/OuterComposite.java
index e84d45d18e31..f8d4c3f941fb 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -143,10 +143,7 @@ public class OuterComposite  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Pet.java
index f06ef8ff659e..63a51afec8e6 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Pet.java
@@ -286,10 +286,7 @@ public class Pet  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index f4d21aa03c16..5d28308afff0 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -115,10 +115,7 @@ public class ReadOnlyFirst  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/SpecialModelName.java
index 42d3f12db0d2..f5abe25c3073 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -89,10 +89,7 @@ public class SpecialModelName  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Tag.java
index 55dc2183a78c..532d5c4e9cd6 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/Tag.java
@@ -115,10 +115,7 @@ public class Tag  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/TypeHolderDefault.java
index 8dba45ae2232..8b62d3bb43ff 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/TypeHolderDefault.java
@@ -208,10 +208,7 @@ public class TypeHolderDefault  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/TypeHolderExample.java
index 425072268896..9dcb8e083646 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/TypeHolderExample.java
@@ -235,10 +235,7 @@ public class TypeHolderExample  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/User.java
index 39d1f709e266..c771fba3559e 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/User.java
@@ -277,10 +277,7 @@ public class User  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/XmlItem.java
index f4f835cf85e6..a6b0f6fe479d 100644
--- a/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/jaxrs-datelib-j8/src/gen/java/org/openapitools/model/XmlItem.java
@@ -920,10 +920,7 @@ public class XmlItem  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index 05eefe44c427..01bc920885ad 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -132,10 +132,7 @@ public class AdditionalPropertiesClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
index 1d937aff06a2..78a13ee86d04 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
@@ -116,10 +116,7 @@ public class AllOfWithSingleRef   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Animal.java
index 558e953eedcd..74960f8953f9 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Animal.java
@@ -122,10 +122,7 @@ public class Animal   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 39d01b0ed8c3..ebf0177cf227 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -99,10 +99,7 @@ public class ArrayOfArrayOfNumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index c17cabc119a6..c3f5af823bfa 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -99,10 +99,7 @@ public class ArrayOfNumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ArrayTest.java
index 5e4ec5d4f13f..13eb005ccd86 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -169,10 +169,7 @@ public class ArrayTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Capitalization.java
index 7ca5a13d911f..2806b5416bc7 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Capitalization.java
@@ -222,10 +222,7 @@ public class Capitalization   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Cat.java
index e6e62d1bc74d..78118e85fb4d 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Cat.java
@@ -88,10 +88,7 @@ public class Cat extends Animal  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Category.java
index 1d36b09d30af..8b05a1a68175 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Category.java
@@ -114,10 +114,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ChildWithNullable.java
index 5cae27fc3e56..3d9474011db0 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ChildWithNullable.java
@@ -89,10 +89,7 @@ public class ChildWithNullable extends ParentWithNullable  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ClassModel.java
index 478bf3f95e7e..439464826bf7 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ClassModel.java
@@ -88,10 +88,7 @@ public class ClassModel   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Client.java
index 8f881c97371b..918a88b806b4 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Client.java
@@ -87,10 +87,7 @@ public class Client   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/DeprecatedObject.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/DeprecatedObject.java
index 1fd923cbc5e4..fcc96e095202 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/DeprecatedObject.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/DeprecatedObject.java
@@ -87,10 +87,7 @@ public class DeprecatedObject   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Dog.java
index d1fc941df4c7..936cbe12693e 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Dog.java
@@ -88,10 +88,7 @@ public class Dog extends Animal  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/EnumArrays.java
index f72eade5fa15..1bbd6342754b 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -196,10 +196,7 @@ public class EnumArrays   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/EnumTest.java
index 64308f0b1434..b7300c741bbd 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/EnumTest.java
@@ -426,10 +426,7 @@ public class EnumTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
index 89e7674e0300..4490f94f5a2f 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
@@ -126,10 +126,7 @@ public class FakeBigDecimalMap200Response   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index 9ed8062dd343..50a92afa4892 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -126,10 +126,7 @@ public class FileSchemaTestClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Foo.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Foo.java
index 171c22420436..0c119adb0a42 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Foo.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Foo.java
@@ -87,10 +87,7 @@ public class Foo   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
index 068deb788b7f..510a1f271b71 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
@@ -89,10 +89,7 @@ public class FooGetDefaultResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/FormatTest.java
index baf048c6db43..2f37e7fca72c 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/FormatTest.java
@@ -507,10 +507,7 @@ public class FormatTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index 47a891575bda..af1ecd81421d 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -115,10 +115,7 @@ public class HasOnlyReadOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/HealthCheckResult.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/HealthCheckResult.java
index cde431de4692..969c041592bd 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/HealthCheckResult.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/HealthCheckResult.java
@@ -88,10 +88,7 @@ public class HealthCheckResult   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/MapTest.java
index 58a3a424d794..99e03adcec4f 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/MapTest.java
@@ -238,10 +238,7 @@ public class MapTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 5157e670f8ee..df811952325b 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -154,10 +154,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Model200Response.java
index 0d12263dbdf0..07781b9f11c4 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Model200Response.java
@@ -116,10 +116,7 @@ public class Model200Response   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ModelApiResponse.java
index 3dcf34bc5606..2d882ae5976b 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -142,10 +142,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ModelFile.java
index 1bc030e82c37..756b00b368ae 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ModelFile.java
@@ -89,10 +89,7 @@ public class ModelFile   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ModelList.java
index 5f26ea12bb17..effad15abf2d 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ModelList.java
@@ -88,10 +88,7 @@ public class ModelList   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ModelReturn.java
index 91d03d132be2..4306f84f09d0 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -89,10 +89,7 @@ public class ModelReturn   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Name.java
index 3231583b54d3..2698e7f41009 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Name.java
@@ -169,10 +169,7 @@ public class Name   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/NullableClass.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/NullableClass.java
index d13e3328c97f..7f5567baa26c 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/NullableClass.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/NullableClass.java
@@ -439,10 +439,7 @@ public class NullableClass extends HashMap<String, Object>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/NumberOnly.java
index 99dd85b36b77..077c0e1efd00 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -88,10 +88,7 @@ public class NumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
index 416f20f48559..f8d48b341914 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
@@ -181,10 +181,7 @@ public class ObjectWithDeprecatedFields   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Order.java
index d472ca78fc30..3da99fd3daec 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Order.java
@@ -261,10 +261,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/OuterComposite.java
index c68c6e264ed9..3ca574aa9f9a 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -142,10 +142,7 @@ public class OuterComposite   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
index fb224873476a..719d38a73b6b 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
@@ -89,10 +89,7 @@ public class OuterObjectWithEnumProperty   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ParentWithNullable.java
index dc27ecc2c839..0f0f83340606 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ParentWithNullable.java
@@ -155,10 +155,7 @@ public class ParentWithNullable   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Pet.java
index b956ce77f47c..76018769ca41 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Pet.java
@@ -285,10 +285,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index 0551515f6868..b3fd6e72e285 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -114,10 +114,7 @@ public class ReadOnlyFirst   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/SpecialModelName.java
index 7eae6c443365..41df6d64217b 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -88,10 +88,7 @@ public class SpecialModelName   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Tag.java
index ecf2d1686a1d..40390efdfe55 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/Tag.java
@@ -114,10 +114,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 20813947ba09..b594b7fc9048 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -90,10 +90,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/User.java
index f58bb3499cbf..5426fb9dafb6 100644
--- a/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/User.java
@@ -276,10 +276,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/Category.java
index 28651d5450ae..e3b6cf669c62 100644
--- a/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/Category.java
@@ -75,10 +75,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/ModelApiResponse.java
index c351ec245dea..cea81ebf78c9 100644
--- a/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -91,10 +91,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/Order.java
index ba9eb5e7e9ab..c0c9aa08dfcb 100644
--- a/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/Order.java
@@ -161,10 +161,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/Pet.java
index 13bd42f90182..6d0a16c5c616 100644
--- a/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/Pet.java
@@ -169,10 +169,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/Tag.java
index 3bbd8e2464b8..3202e01e2632 100644
--- a/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/Tag.java
@@ -75,10 +75,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/User.java
index 1899478a44c5..16f3bb6ecc77 100644
--- a/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-resteasy/default/src/gen/java/org/openapitools/model/User.java
@@ -166,10 +166,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/Category.java
index 156d1faf9180..ecaacb3bf4d2 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/Category.java
@@ -75,10 +75,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/ModelApiResponse.java
index d84d2a74c098..bf105bc201ff 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -91,10 +91,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/Order.java
index 7e8a478e8944..3a6dfedc0a66 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/Order.java
@@ -161,10 +161,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/Pet.java
index 5e61cf655010..f2000a952996 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/Pet.java
@@ -167,10 +167,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/Tag.java
index 01bab9ade81f..f60564184e16 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/Tag.java
@@ -75,10 +75,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/User.java
index 02fc56623094..a5da406f64ba 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap-java8/src/gen/java/org/openapitools/model/User.java
@@ -166,10 +166,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/Category.java
index 156d1faf9180..ecaacb3bf4d2 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/Category.java
@@ -75,10 +75,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/ModelApiResponse.java
index d84d2a74c098..bf105bc201ff 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -91,10 +91,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/Order.java
index 78498fbbe636..49b217e37977 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/Order.java
@@ -161,10 +161,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/Pet.java
index 5e61cf655010..f2000a952996 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/Pet.java
@@ -167,10 +167,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/Tag.java
index 01bab9ade81f..f60564184e16 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/Tag.java
@@ -75,10 +75,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/User.java
index 02fc56623094..a5da406f64ba 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap-joda/src/gen/java/org/openapitools/model/User.java
@@ -166,10 +166,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/Category.java
index 156d1faf9180..ecaacb3bf4d2 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/Category.java
@@ -75,10 +75,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/ModelApiResponse.java
index d84d2a74c098..bf105bc201ff 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -91,10 +91,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/Order.java
index 01575aa1a539..d1ccc69cb5fd 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/Order.java
@@ -161,10 +161,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/Pet.java
index 5e61cf655010..f2000a952996 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/Pet.java
@@ -167,10 +167,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/Tag.java
index 01bab9ade81f..f60564184e16 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/Tag.java
@@ -75,10 +75,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/User.java
index 02fc56623094..a5da406f64ba 100644
--- a/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-resteasy/eap/src/gen/java/org/openapitools/model/User.java
@@ -166,10 +166,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/Category.java
index 28651d5450ae..e3b6cf669c62 100644
--- a/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/Category.java
@@ -75,10 +75,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/ModelApiResponse.java
index c351ec245dea..cea81ebf78c9 100644
--- a/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -91,10 +91,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/Order.java
index ef586d556bc7..7f380f5d2936 100644
--- a/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/Order.java
@@ -161,10 +161,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/Pet.java
index 13bd42f90182..6d0a16c5c616 100644
--- a/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/Pet.java
@@ -169,10 +169,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/Tag.java
index 3bbd8e2464b8..3202e01e2632 100644
--- a/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/Tag.java
@@ -75,10 +75,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/User.java
index 1899478a44c5..16f3bb6ecc77 100644
--- a/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-resteasy/java8/src/gen/java/org/openapitools/model/User.java
@@ -166,10 +166,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/Category.java
index 28651d5450ae..e3b6cf669c62 100644
--- a/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/Category.java
@@ -75,10 +75,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/ModelApiResponse.java
index c351ec245dea..cea81ebf78c9 100644
--- a/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -91,10 +91,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/Order.java
index a3e14c573572..3cb0e82bdcbc 100644
--- a/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/Order.java
@@ -161,10 +161,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/Pet.java
index 13bd42f90182..6d0a16c5c616 100644
--- a/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/Pet.java
@@ -169,10 +169,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/Tag.java
index 3bbd8e2464b8..3202e01e2632 100644
--- a/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/Tag.java
@@ -75,10 +75,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/User.java
index 1899478a44c5..16f3bb6ecc77 100644
--- a/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-resteasy/joda/src/gen/java/org/openapitools/model/User.java
@@ -166,10 +166,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index c87bab9ec0a1..0fe4e6c4859d 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -115,10 +115,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object> impleme
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
index 8bef5968634e..1a27e67db719 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -116,10 +116,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List> implements
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 11fceae099c3..69dbf6a1c972 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -115,10 +115,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean> implem
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index 3d63d291e865..5a12fdb5c6d2 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -428,10 +428,7 @@ public class AdditionalPropertiesClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
index da6d04d4c362..f31f4e774aa9 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -115,10 +115,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer> implem
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
index e78af6bae076..dfa65c5fa68c 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -116,10 +116,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal> impl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
index 51a593c8b582..c3bc5dbc001d 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -115,10 +115,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map> implements
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
index 28e7fa1477a7..219681161b36 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -115,10 +115,7 @@ public class AdditionalPropertiesString extends HashMap<String, String> implemen
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Animal.java
index 652a03ecb14d..e0cf4edc8482 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Animal.java
@@ -114,10 +114,7 @@ public class Animal  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index bde87f736cc1..7ecda87ac2d6 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -96,10 +96,7 @@ public class ArrayOfArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index 3f869d7270a3..77f1dac47836 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -96,10 +96,7 @@ public class ArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ArrayTest.java
index ef696281a341..9257b136d4a5 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -172,10 +172,7 @@ public class ArrayTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/BigCat.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/BigCat.java
index 2990e09fb550..94e6ef10a7d3 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/BigCat.java
@@ -134,10 +134,7 @@ public class BigCat extends Cat implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Capitalization.java
index 493f706a54d4..108c0d55267b 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Capitalization.java
@@ -187,10 +187,7 @@ public class Capitalization  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Cat.java
index 04cdc67b7f08..e57230d3891f 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Cat.java
@@ -87,10 +87,7 @@ public class Cat extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Category.java
index 48c8673299f4..96b68bbbc428 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Category.java
@@ -105,10 +105,7 @@ public class Category  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ClassModel.java
index e04b5ca98057..0c0f8236dd0d 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ClassModel.java
@@ -78,10 +78,7 @@ public class ClassModel  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Client.java
index 205d41a45d5a..5a2e3de515c1 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Client.java
@@ -76,10 +76,7 @@ public class Client  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Dog.java
index 12a1ce8e794b..6f41bb1119b4 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Dog.java
@@ -87,10 +87,7 @@ public class Dog extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/EnumArrays.java
index 584e892776f4..b625039cf477 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -211,10 +211,7 @@ public class EnumArrays  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/EnumTest.java
index b16406abe104..0ae35e476cab 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/EnumTest.java
@@ -361,10 +361,7 @@ public class EnumTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index d0de13f788ae..c7331daff4ca 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -118,10 +118,7 @@ public class FileSchemaTestClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/FormatTest.java
index d780288ce8ee..e61457f13924 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/FormatTest.java
@@ -392,10 +392,7 @@ public class FormatTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index 5bdf65c3b33b..4fbe96b53f74 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -99,10 +99,7 @@ public class HasOnlyReadOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/MapTest.java
index 2f2ffb53db43..d36e979b5b7a 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/MapTest.java
@@ -255,10 +255,7 @@ public class MapTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 1bfb9f9655e1..8e19d49a0580 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -141,10 +141,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Model200Response.java
index 6f1cbc40c759..fc71ff6a467e 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Model200Response.java
@@ -101,10 +101,7 @@ public class Model200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ModelApiResponse.java
index 4cd19fcda09a..c3f915266958 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -121,10 +121,7 @@ public class ModelApiResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ModelFile.java
index 7c99801a543f..b35e574b6e59 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ModelFile.java
@@ -80,10 +80,7 @@ public class ModelFile  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ModelList.java
index f2342fd766c6..e0c0ff8a3eed 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ModelList.java
@@ -77,10 +77,7 @@ public class ModelList  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ModelReturn.java
index 59c05f0ba41d..4ec380861671 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -79,10 +79,7 @@ public class ModelReturn  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Name.java
index d743c8108498..cea8f06ea2e2 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Name.java
@@ -151,10 +151,7 @@ public class Name  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/NumberOnly.java
index 50e6e3b295d2..5835aeca5ace 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -77,10 +77,7 @@ public class NumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Order.java
index 3fb43b002058..a35fc21dd4be 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Order.java
@@ -235,10 +235,7 @@ public class Order  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/OuterComposite.java
index 2f6f1fbb8d76..882de992e527 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -121,10 +121,7 @@ public class OuterComposite  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Pet.java
index e9728af94b0e..ffd13edf4a35 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Pet.java
@@ -284,10 +284,7 @@ public class Pet  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index 12dcac9ef9d7..62ba902d9929 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -98,10 +98,7 @@ public class ReadOnlyFirst  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/SpecialModelName.java
index d322066cf3aa..f9668dde3c5d 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -77,10 +77,7 @@ public class SpecialModelName  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Tag.java
index 845902b49d84..cb41d8fbc4ea 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/Tag.java
@@ -98,10 +98,7 @@ public class Tag  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/TypeHolderDefault.java
index 6ad1a947a382..c7d68bde6476 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/TypeHolderDefault.java
@@ -199,10 +199,7 @@ public class TypeHolderDefault  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/TypeHolderExample.java
index b3dd6f469d6c..5fbfc75d8cda 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/TypeHolderExample.java
@@ -223,10 +223,7 @@ public class TypeHolderExample  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/User.java
index 7ec64ff55b63..a6fbe66d34f9 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/User.java
@@ -231,10 +231,7 @@ public class User  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/XmlItem.java
index b29ccf9e1d83..64d83c3d3611 100644
--- a/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/jaxrs-spec-interface-response/src/gen/java/org/openapitools/model/XmlItem.java
@@ -840,10 +840,7 @@ public class XmlItem  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index c87bab9ec0a1..0fe4e6c4859d 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -115,10 +115,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object> impleme
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
index 8bef5968634e..1a27e67db719 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -116,10 +116,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List> implements
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 11fceae099c3..69dbf6a1c972 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -115,10 +115,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean> implem
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index 3d63d291e865..5a12fdb5c6d2 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -428,10 +428,7 @@ public class AdditionalPropertiesClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
index da6d04d4c362..f31f4e774aa9 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -115,10 +115,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer> implem
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
index e78af6bae076..dfa65c5fa68c 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -116,10 +116,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal> impl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
index 51a593c8b582..c3bc5dbc001d 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -115,10 +115,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map> implements
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
index 28e7fa1477a7..219681161b36 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -115,10 +115,7 @@ public class AdditionalPropertiesString extends HashMap<String, String> implemen
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Animal.java
index 652a03ecb14d..e0cf4edc8482 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Animal.java
@@ -114,10 +114,7 @@ public class Animal  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index bde87f736cc1..7ecda87ac2d6 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -96,10 +96,7 @@ public class ArrayOfArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index 3f869d7270a3..77f1dac47836 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -96,10 +96,7 @@ public class ArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ArrayTest.java
index ef696281a341..9257b136d4a5 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -172,10 +172,7 @@ public class ArrayTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/BigCat.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/BigCat.java
index 2990e09fb550..94e6ef10a7d3 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/BigCat.java
@@ -134,10 +134,7 @@ public class BigCat extends Cat implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Capitalization.java
index 493f706a54d4..108c0d55267b 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Capitalization.java
@@ -187,10 +187,7 @@ public class Capitalization  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Cat.java
index 04cdc67b7f08..e57230d3891f 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Cat.java
@@ -87,10 +87,7 @@ public class Cat extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Category.java
index 48c8673299f4..96b68bbbc428 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Category.java
@@ -105,10 +105,7 @@ public class Category  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ClassModel.java
index e04b5ca98057..0c0f8236dd0d 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ClassModel.java
@@ -78,10 +78,7 @@ public class ClassModel  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Client.java
index 205d41a45d5a..5a2e3de515c1 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Client.java
@@ -76,10 +76,7 @@ public class Client  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Dog.java
index 12a1ce8e794b..6f41bb1119b4 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Dog.java
@@ -87,10 +87,7 @@ public class Dog extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/EnumArrays.java
index 584e892776f4..b625039cf477 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -211,10 +211,7 @@ public class EnumArrays  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/EnumTest.java
index b16406abe104..0ae35e476cab 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/EnumTest.java
@@ -361,10 +361,7 @@ public class EnumTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index d0de13f788ae..c7331daff4ca 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -118,10 +118,7 @@ public class FileSchemaTestClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/FormatTest.java
index d780288ce8ee..e61457f13924 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/FormatTest.java
@@ -392,10 +392,7 @@ public class FormatTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index 5bdf65c3b33b..4fbe96b53f74 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -99,10 +99,7 @@ public class HasOnlyReadOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/MapTest.java
index 2f2ffb53db43..d36e979b5b7a 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/MapTest.java
@@ -255,10 +255,7 @@ public class MapTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 1bfb9f9655e1..8e19d49a0580 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -141,10 +141,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Model200Response.java
index 6f1cbc40c759..fc71ff6a467e 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Model200Response.java
@@ -101,10 +101,7 @@ public class Model200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ModelApiResponse.java
index 4cd19fcda09a..c3f915266958 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -121,10 +121,7 @@ public class ModelApiResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ModelFile.java
index 7c99801a543f..b35e574b6e59 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ModelFile.java
@@ -80,10 +80,7 @@ public class ModelFile  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ModelList.java
index f2342fd766c6..e0c0ff8a3eed 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ModelList.java
@@ -77,10 +77,7 @@ public class ModelList  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ModelReturn.java
index 59c05f0ba41d..4ec380861671 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -79,10 +79,7 @@ public class ModelReturn  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Name.java
index d743c8108498..cea8f06ea2e2 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Name.java
@@ -151,10 +151,7 @@ public class Name  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/NumberOnly.java
index 50e6e3b295d2..5835aeca5ace 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -77,10 +77,7 @@ public class NumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Order.java
index 3fb43b002058..a35fc21dd4be 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Order.java
@@ -235,10 +235,7 @@ public class Order  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/OuterComposite.java
index 2f6f1fbb8d76..882de992e527 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -121,10 +121,7 @@ public class OuterComposite  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Pet.java
index e9728af94b0e..ffd13edf4a35 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Pet.java
@@ -284,10 +284,7 @@ public class Pet  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index 12dcac9ef9d7..62ba902d9929 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -98,10 +98,7 @@ public class ReadOnlyFirst  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/SpecialModelName.java
index d322066cf3aa..f9668dde3c5d 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -77,10 +77,7 @@ public class SpecialModelName  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Tag.java
index 845902b49d84..cb41d8fbc4ea 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/Tag.java
@@ -98,10 +98,7 @@ public class Tag  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/TypeHolderDefault.java
index 6ad1a947a382..c7d68bde6476 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/TypeHolderDefault.java
@@ -199,10 +199,7 @@ public class TypeHolderDefault  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/TypeHolderExample.java
index b3dd6f469d6c..5fbfc75d8cda 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/TypeHolderExample.java
@@ -223,10 +223,7 @@ public class TypeHolderExample  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/User.java
index 7ec64ff55b63..a6fbe66d34f9 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/User.java
@@ -231,10 +231,7 @@ public class User  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/XmlItem.java
index b29ccf9e1d83..64d83c3d3611 100644
--- a/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/jaxrs-spec-interface/src/gen/java/org/openapitools/model/XmlItem.java
@@ -840,10 +840,7 @@ public class XmlItem  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index 84dfc990486d..c0547e3b97d0 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -115,10 +115,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object> impleme
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
index ff5051389f5c..72ff5968000d 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -116,10 +116,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List> implements
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 4a90e7d78df7..df993faf4a4c 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -115,10 +115,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean> implem
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index 78c62a2a4dd0..7dc752b75c93 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -442,10 +442,7 @@ public class AdditionalPropertiesClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 9466dac9156c..4b2df008933a 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -115,10 +115,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer> implem
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
index 975768f21c1a..4227c3b92a32 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -116,10 +116,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal> impl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
index 3357c517b8aa..e09288fa264f 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -115,10 +115,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map> implements
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
index 1dfffcf71d11..413c0afbdf73 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -115,10 +115,7 @@ public class AdditionalPropertiesString extends HashMap<String, String> implemen
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Animal.java
index ff872bf66fd2..14705ff28e9a 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Animal.java
@@ -119,10 +119,7 @@ public class Animal  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 7012c62e7be0..256ed68d3a22 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -100,10 +100,7 @@ public class ArrayOfArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index 23f40ffccc0c..aca23ff9beef 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -100,10 +100,7 @@ public class ArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ArrayTest.java
index 5b3762bf20fb..bfcc1ad358b1 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -178,10 +178,7 @@ public class ArrayTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/BigCat.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/BigCat.java
index 46662fd892b6..d1178d279ecf 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/BigCat.java
@@ -139,10 +139,7 @@ public class BigCat extends Cat implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Capitalization.java
index d37d3c8d0cc7..fe31bec5c1e3 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Capitalization.java
@@ -196,10 +196,7 @@ public class Capitalization  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Cat.java
index c6fc2552f719..fd3a12911a86 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Cat.java
@@ -92,10 +92,7 @@ public class Cat extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Category.java
index 5cfbf588794a..3c213dfdd1b6 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Category.java
@@ -110,10 +110,7 @@ public class Category  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ClassModel.java
index 7b0d3ab50339..65ab9990d4b4 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ClassModel.java
@@ -82,10 +82,7 @@ public class ClassModel  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Client.java
index b36c49abffca..3753ca3fc034 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Client.java
@@ -80,10 +80,7 @@ public class Client  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Dog.java
index 1db99df0b086..42ab0c69aee2 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Dog.java
@@ -92,10 +92,7 @@ public class Dog extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/EnumArrays.java
index 944e62fb1769..98a7773a5962 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -216,10 +216,7 @@ public class EnumArrays  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/EnumTest.java
index 2c9ddf6e10cd..89a9b00f5e6b 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/EnumTest.java
@@ -369,10 +369,7 @@ public class EnumTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index 681197b36eff..4b583f9e8831 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -123,10 +123,7 @@ public class FileSchemaTestClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/FormatTest.java
index 640e29f97e1b..f5657728ca41 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/FormatTest.java
@@ -409,10 +409,7 @@ public class FormatTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index a6012f97bdbb..ed1890532d3c 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/MapTest.java
index 995dfe729c9a..50410e1b36fa 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/MapTest.java
@@ -262,10 +262,7 @@ public class MapTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 2888934973e7..586f6b7a1331 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -147,10 +147,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Model200Response.java
index d76dcf28b6f1..15fdeb4954d3 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Model200Response.java
@@ -106,10 +106,7 @@ public class Model200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ModelApiResponse.java
index 0efb040ccbff..45f3e3025dc4 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -127,10 +127,7 @@ public class ModelApiResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ModelFile.java
index 56c99dd4b1c2..295beef1303a 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ModelFile.java
@@ -84,10 +84,7 @@ public class ModelFile  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ModelList.java
index a72acfc92f1c..bbfd56c5a02e 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ModelList.java
@@ -81,10 +81,7 @@ public class ModelList  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ModelReturn.java
index b958abe3a6bb..6457f0ee712f 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -83,10 +83,7 @@ public class ModelReturn  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Name.java
index 58749e89702a..460035f7d5e1 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Name.java
@@ -158,10 +158,7 @@ public class Name  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/NumberOnly.java
index 2016a831b42b..27e0cf326c9a 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -81,10 +81,7 @@ public class NumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Order.java
index 3bdc559f29c3..d10cc94b1876 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Order.java
@@ -244,10 +244,7 @@ public class Order  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/OuterComposite.java
index e845c9f3b762..1973363921a6 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -127,10 +127,7 @@ public class OuterComposite  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Pet.java
index f22e96f8b834..362e8c0c4b0c 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Pet.java
@@ -293,10 +293,7 @@ public class Pet  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index 6ce270e99b69..a6aa1cf7deab 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -103,10 +103,7 @@ public class ReadOnlyFirst  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/SpecialModelName.java
index 362495aeec4b..adf10918951c 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -81,10 +81,7 @@ public class SpecialModelName  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Tag.java
index 492121d8fc80..595b8d96748b 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/Tag.java
@@ -103,10 +103,7 @@ public class Tag  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/TypeHolderDefault.java
index 78d8924d5d74..a18b3aae3917 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/TypeHolderDefault.java
@@ -207,10 +207,7 @@ public class TypeHolderDefault  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/TypeHolderExample.java
index e4cc29df7a0a..f04068330e99 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/TypeHolderExample.java
@@ -232,10 +232,7 @@ public class TypeHolderExample  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/User.java
index 6cf973596577..e2fc00709bb6 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/User.java
@@ -242,10 +242,7 @@ public class User  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/XmlItem.java
index a05e90cc22ce..a7cd1a854194 100644
--- a/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/jaxrs-spec-jakarta/src/gen/java/org/openapitools/model/XmlItem.java
@@ -872,10 +872,7 @@ public class XmlItem  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index 2548e2a567e4..1fcd9741c36a 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -113,10 +113,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object> impleme
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
index 4718be40b9f5..d997da527c06 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -114,10 +114,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List> implements
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index e5cdbf3fca10..d5626d58bca4 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -113,10 +113,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean> implem
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index d87540eaeb48..ecf0adaeacac 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -440,10 +440,7 @@ public class AdditionalPropertiesClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
index c8a685acf788..20386b796a63 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -113,10 +113,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer> implem
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
index 3fef6b2e97fd..f0af5119c98b 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -114,10 +114,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal> impl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
index c6d556f2af56..39ed7b4f3b7c 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -113,10 +113,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map> implements
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
index fd67d3041d19..0e6b40f11403 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -113,10 +113,7 @@ public class AdditionalPropertiesString extends HashMap<String, String> implemen
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Animal.java
index 6de8f353d78f..6ef4438ffdb2 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Animal.java
@@ -117,10 +117,7 @@ public class Animal  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 43642d3a4575..52982e95b263 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -98,10 +98,7 @@ public class ArrayOfArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index 04dffe2e4fd5..7e6bd384c605 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -98,10 +98,7 @@ public class ArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ArrayTest.java
index c6d1170af69b..d284ff0c4558 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -176,10 +176,7 @@ public class ArrayTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/BigCat.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/BigCat.java
index f18b41b1c616..be258f990e32 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/BigCat.java
@@ -137,10 +137,7 @@ public class BigCat extends Cat implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Capitalization.java
index 3d6327b62eb3..a92fe13c1979 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Capitalization.java
@@ -194,10 +194,7 @@ public class Capitalization  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Cat.java
index b469192c3f88..6b316ed7ba70 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Cat.java
@@ -90,10 +90,7 @@ public class Cat extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Category.java
index 68f38cd35bc6..8cd84e08aeac 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Category.java
@@ -108,10 +108,7 @@ public class Category  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ClassModel.java
index 9855383cc28b..31234d5ec7e7 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ClassModel.java
@@ -80,10 +80,7 @@ public class ClassModel  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Client.java
index 75ae910e1012..504ee47c7de2 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Client.java
@@ -78,10 +78,7 @@ public class Client  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Dog.java
index 704774119cd8..be82ca88d7df 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Dog.java
@@ -90,10 +90,7 @@ public class Dog extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/EnumArrays.java
index 9b3a24ba84f0..47de2d53cecf 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -214,10 +214,7 @@ public class EnumArrays  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/EnumTest.java
index 049e168a2732..cccfea475a65 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/EnumTest.java
@@ -367,10 +367,7 @@ public class EnumTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index 47cbef614b40..8fd4b42f6b2c 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -121,10 +121,7 @@ public class FileSchemaTestClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/FormatTest.java
index 1303594cfaea..80826de1c96d 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/FormatTest.java
@@ -407,10 +407,7 @@ public class FormatTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index c5e3d0f9326a..b1a670a0538b 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -102,10 +102,7 @@ public class HasOnlyReadOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/MapTest.java
index 9004c86def2a..09ae7fdd488a 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/MapTest.java
@@ -260,10 +260,7 @@ public class MapTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 8369cda52c62..b9ae30c1be2d 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -145,10 +145,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Model200Response.java
index f932c5f63012..2d71a9bd8684 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Model200Response.java
@@ -104,10 +104,7 @@ public class Model200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ModelApiResponse.java
index d5ee477fd7f9..63694f1d65a4 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -125,10 +125,7 @@ public class ModelApiResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ModelFile.java
index 66c153992049..8b4895030930 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ModelFile.java
@@ -82,10 +82,7 @@ public class ModelFile  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ModelList.java
index 4f2aea31fe73..66f17af3eeab 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ModelList.java
@@ -79,10 +79,7 @@ public class ModelList  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ModelReturn.java
index 1ca638eb87e6..7a5175e8de29 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -81,10 +81,7 @@ public class ModelReturn  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Name.java
index 7df41edae0d5..0095f3672e05 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Name.java
@@ -156,10 +156,7 @@ public class Name  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/NumberOnly.java
index 32313b7035df..3e348e28456e 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -79,10 +79,7 @@ public class NumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Order.java
index bfe4f95642d3..cc2aa2301858 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Order.java
@@ -242,10 +242,7 @@ public class Order  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/OuterComposite.java
index df4fae257df3..4069a95e186b 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -125,10 +125,7 @@ public class OuterComposite  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Pet.java
index 36f1ec55c4a0..b27f4c47c438 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Pet.java
@@ -291,10 +291,7 @@ public class Pet  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index 4a17dc465694..63aac5066e69 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -101,10 +101,7 @@ public class ReadOnlyFirst  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/SpecialModelName.java
index bd618e38d7c8..c6ea3b6efbe4 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -79,10 +79,7 @@ public class SpecialModelName  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Tag.java
index 04e6fe243221..b9ca75baf0b0 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/Tag.java
@@ -101,10 +101,7 @@ public class Tag  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/TypeHolderDefault.java
index e8c388a9f006..20b73c035941 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/TypeHolderDefault.java
@@ -205,10 +205,7 @@ public class TypeHolderDefault  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/TypeHolderExample.java
index e8a19fb41d31..aab0ea0c1aed 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/TypeHolderExample.java
@@ -230,10 +230,7 @@ public class TypeHolderExample  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/User.java
index d18c4e7da56a..343358a4ee1c 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/User.java
@@ -240,10 +240,7 @@ public class User  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/XmlItem.java
index 795543ae2101..df8198aca61a 100644
--- a/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/jaxrs-spec-microprofile-openapi-annotations/src/gen/java/org/openapitools/model/XmlItem.java
@@ -870,10 +870,7 @@ public class XmlItem  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index 4da31a758385..a32cca5d1791 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -135,10 +135,7 @@ public class AdditionalPropertiesClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
index 6ffd6a67036d..acde25c63f1d 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
@@ -102,10 +102,7 @@ public class AllOfWithSingleRef  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Animal.java
index 3e4ba7c535ed..cdb0c03b1e48 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Animal.java
@@ -116,10 +116,7 @@ public class Animal  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 43642d3a4575..52982e95b263 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -98,10 +98,7 @@ public class ArrayOfArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index 04dffe2e4fd5..7e6bd384c605 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -98,10 +98,7 @@ public class ArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ArrayTest.java
index f082e06702a0..1816f6528257 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -176,10 +176,7 @@ public class ArrayTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Capitalization.java
index 3d6327b62eb3..a92fe13c1979 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Capitalization.java
@@ -194,10 +194,7 @@ public class Capitalization  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Cat.java
index b469192c3f88..6b316ed7ba70 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Cat.java
@@ -90,10 +90,7 @@ public class Cat extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Category.java
index 68f38cd35bc6..8cd84e08aeac 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Category.java
@@ -108,10 +108,7 @@ public class Category  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ChildWithNullable.java
index a7101e0f223f..22321fd5c504 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ChildWithNullable.java
@@ -82,10 +82,7 @@ public class ChildWithNullable extends ParentWithNullable implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ClassModel.java
index 9855383cc28b..31234d5ec7e7 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ClassModel.java
@@ -80,10 +80,7 @@ public class ClassModel  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Client.java
index 75ae910e1012..504ee47c7de2 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Client.java
@@ -78,10 +78,7 @@ public class Client  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/DeprecatedObject.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/DeprecatedObject.java
index e9e1367d05d9..d1ba6acc53a6 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/DeprecatedObject.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/DeprecatedObject.java
@@ -78,10 +78,7 @@ public class DeprecatedObject  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Dog.java
index 704774119cd8..be82ca88d7df 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Dog.java
@@ -90,10 +90,7 @@ public class Dog extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/EnumArrays.java
index 9b3a24ba84f0..47de2d53cecf 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -214,10 +214,7 @@ public class EnumArrays  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/EnumTest.java
index 62d1ac83f8e0..6939f1ca0179 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/EnumTest.java
@@ -440,10 +440,7 @@ public class EnumTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
index 4faf0d694228..06d261f85885 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
@@ -121,10 +121,7 @@ public class FakeBigDecimalMap200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index 47cbef614b40..8fd4b42f6b2c 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -121,10 +121,7 @@ public class FileSchemaTestClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Foo.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Foo.java
index 15951718c006..ea5176e4b989 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Foo.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Foo.java
@@ -78,10 +78,7 @@ public class Foo  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
index a5318b9c3583..f8bc1376e7b6 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
@@ -80,10 +80,7 @@ public class FooGetDefaultResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/FormatTest.java
index f45d687d323a..d88bd1a6b3c3 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/FormatTest.java
@@ -455,10 +455,7 @@ public class FormatTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index c5e3d0f9326a..b1a670a0538b 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -102,10 +102,7 @@ public class HasOnlyReadOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/HealthCheckResult.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/HealthCheckResult.java
index cc20ce649f6b..86e165a1e020 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/HealthCheckResult.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/HealthCheckResult.java
@@ -81,10 +81,7 @@ public class HealthCheckResult  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/MapTest.java
index 9004c86def2a..09ae7fdd488a 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/MapTest.java
@@ -260,10 +260,7 @@ public class MapTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 8369cda52c62..b9ae30c1be2d 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -145,10 +145,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Model200Response.java
index f932c5f63012..2d71a9bd8684 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Model200Response.java
@@ -104,10 +104,7 @@ public class Model200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ModelApiResponse.java
index d5ee477fd7f9..63694f1d65a4 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -125,10 +125,7 @@ public class ModelApiResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ModelFile.java
index 66c153992049..8b4895030930 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ModelFile.java
@@ -82,10 +82,7 @@ public class ModelFile  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ModelList.java
index 4f2aea31fe73..66f17af3eeab 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ModelList.java
@@ -79,10 +79,7 @@ public class ModelList  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ModelReturn.java
index 1ca638eb87e6..7a5175e8de29 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -81,10 +81,7 @@ public class ModelReturn  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Name.java
index 7df41edae0d5..0095f3672e05 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Name.java
@@ -156,10 +156,7 @@ public class Name  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/NullableClass.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/NullableClass.java
index c8efa75cfa93..6df275f749de 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/NullableClass.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/NullableClass.java
@@ -458,10 +458,7 @@ public class NullableClass extends HashMap<String, Object> implements Serializab
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/NumberOnly.java
index 32313b7035df..3e348e28456e 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -79,10 +79,7 @@ public class NumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
index a42c8a94ede5..ccfb7fd3a369 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
@@ -168,10 +168,7 @@ public class ObjectWithDeprecatedFields  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Order.java
index bfe4f95642d3..cc2aa2301858 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Order.java
@@ -242,10 +242,7 @@ public class Order  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/OuterComposite.java
index df4fae257df3..4069a95e186b 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -125,10 +125,7 @@ public class OuterComposite  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
index 4e706736766d..97d86aedf481 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
@@ -86,10 +86,7 @@ public class OuterObjectWithEnumProperty  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ParentWithNullable.java
index 2d8febf5a95e..9f4c7b5eb7b3 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ParentWithNullable.java
@@ -156,10 +156,7 @@ public class ParentWithNullable  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Pet.java
index 36f1ec55c4a0..b27f4c47c438 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Pet.java
@@ -291,10 +291,7 @@ public class Pet  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index 4a17dc465694..63aac5066e69 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -101,10 +101,7 @@ public class ReadOnlyFirst  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/SpecialModelName.java
index 43ff5e3c91b1..7a8a103ad0c7 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -79,10 +79,7 @@ public class SpecialModelName  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Tag.java
index 04e6fe243221..b9ca75baf0b0 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/Tag.java
@@ -101,10 +101,7 @@ public class Tag  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
index be3ad292e1e3..c05ddfb43410 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -114,10 +114,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/User.java
index d18c4e7da56a..343358a4ee1c 100644
--- a/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-spec-quarkus-mutiny/src/gen/java/org/openapitools/model/User.java
@@ -240,10 +240,7 @@ public class User  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-required-and-readonly-property/src/gen/java/org/openapitools/model/ReadonlyAndRequiredProperties.java b/samples/server/petstore/jaxrs-spec-required-and-readonly-property/src/gen/java/org/openapitools/model/ReadonlyAndRequiredProperties.java
index 69599d6f3237..ae4dca8452e6 100644
--- a/samples/server/petstore/jaxrs-spec-required-and-readonly-property/src/gen/java/org/openapitools/model/ReadonlyAndRequiredProperties.java
+++ b/samples/server/petstore/jaxrs-spec-required-and-readonly-property/src/gen/java/org/openapitools/model/ReadonlyAndRequiredProperties.java
@@ -158,10 +158,7 @@ public class ReadonlyAndRequiredProperties  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index 5ea57d05d6c3..4b422811f2d0 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -137,10 +137,7 @@ public class AdditionalPropertiesClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
index f6b3ed24a3a2..d2c4fe08862a 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
@@ -104,10 +104,7 @@ public class AllOfWithSingleRef  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Animal.java
index 147806907874..e58eadc74279 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Animal.java
@@ -118,10 +118,7 @@ public class Animal  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index f4410ea7fa6d..7e9590f48d21 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -100,10 +100,7 @@ public class ArrayOfArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index 998607f2662b..9f16ed7c02ee 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -100,10 +100,7 @@ public class ArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ArrayTest.java
index 9255ad844c8c..970dba759cc5 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -178,10 +178,7 @@ public class ArrayTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Capitalization.java
index e1451b75fa59..b15c2d95c196 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Capitalization.java
@@ -196,10 +196,7 @@ public class Capitalization  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Cat.java
index 459ccab73465..03c6b71e923c 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Cat.java
@@ -92,10 +92,7 @@ public class Cat extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Category.java
index b75f24e99f71..605bffc8b0f8 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Category.java
@@ -110,10 +110,7 @@ public class Category  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ChildWithNullable.java
index 3c30e7d7b0a8..6f074c7f3ce2 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ChildWithNullable.java
@@ -84,10 +84,7 @@ public class ChildWithNullable extends ParentWithNullable implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ClassModel.java
index be44a0dff5b4..a3a78265ab94 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ClassModel.java
@@ -82,10 +82,7 @@ public class ClassModel  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Client.java
index 3a9f1b451e09..4a8739cd5b85 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Client.java
@@ -80,10 +80,7 @@ public class Client  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/DeprecatedObject.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/DeprecatedObject.java
index 5d7d01991586..b5992a2c4c76 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/DeprecatedObject.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/DeprecatedObject.java
@@ -80,10 +80,7 @@ public class DeprecatedObject  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Dog.java
index b3c5f3ea573c..2e1b00f142da 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Dog.java
@@ -92,10 +92,7 @@ public class Dog extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/EnumArrays.java
index 498bb029ccd5..9c92f0e261fd 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -216,10 +216,7 @@ public class EnumArrays  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/EnumTest.java
index d80f8178d14b..a36635f54878 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/EnumTest.java
@@ -442,10 +442,7 @@ public class EnumTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
index 533ee1fb5d60..9c431bfdc2c4 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
@@ -123,10 +123,7 @@ public class FakeBigDecimalMap200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java
index 204519afdfbe..b7085a59be07 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java
@@ -246,10 +246,7 @@ public class FakeTestsDefaultsDefaultResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index bf6e2175c72d..781dda2f0174 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -123,10 +123,7 @@ public class FileSchemaTestClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Foo.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Foo.java
index f6be04545e9f..7ee394dbeeea 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Foo.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Foo.java
@@ -80,10 +80,7 @@ public class Foo  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
index 524ef54678cf..c7416c5772d7 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
@@ -82,10 +82,7 @@ public class FooGetDefaultResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FormatTest.java
index 700e77c1a755..5bd565258905 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/FormatTest.java
@@ -457,10 +457,7 @@ public class FormatTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index bfc989a95b55..4d5dc2f4f23e 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/HealthCheckResult.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/HealthCheckResult.java
index c21ecc8bfd93..a6c0d15e5f19 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/HealthCheckResult.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/HealthCheckResult.java
@@ -83,10 +83,7 @@ public class HealthCheckResult  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/MapTest.java
index ff24115551ab..d3fbb16a45b1 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/MapTest.java
@@ -262,10 +262,7 @@ public class MapTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 74d951cd97a2..bfb433e78efb 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -147,10 +147,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Model200Response.java
index 295d0d5f530a..c3384310e878 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Model200Response.java
@@ -106,10 +106,7 @@ public class Model200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ModelApiResponse.java
index 3c3052b732e1..72e2174ebc93 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -127,10 +127,7 @@ public class ModelApiResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ModelFile.java
index 9627e5c2cb9c..cabe1925f185 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ModelFile.java
@@ -84,10 +84,7 @@ public class ModelFile  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ModelList.java
index 153f3220d19d..8190229f8636 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ModelList.java
@@ -81,10 +81,7 @@ public class ModelList  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ModelReturn.java
index 88f52e904609..71e0ce2a996b 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -83,10 +83,7 @@ public class ModelReturn  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Name.java
index c737650a25ff..d6444623f666 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Name.java
@@ -158,10 +158,7 @@ public class Name  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/NullableClass.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/NullableClass.java
index 49208a56fc3d..27f71a7b7d6c 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/NullableClass.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/NullableClass.java
@@ -460,10 +460,7 @@ public class NullableClass extends HashMap<String, Object> implements Serializab
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/NumberOnly.java
index 199ab5aa0422..a637bddab623 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -81,10 +81,7 @@ public class NumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
index 425c5ec4a59b..36fa9c0a26ef 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
@@ -170,10 +170,7 @@ public class ObjectWithDeprecatedFields  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Order.java
index 4f972f377999..45a86c201672 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Order.java
@@ -244,10 +244,7 @@ public class Order  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/OuterComposite.java
index 9ad100cb4ece..9f15c8ba1f7a 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -127,10 +127,7 @@ public class OuterComposite  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
index 4318bc74a83a..97e7dd3f49ce 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
@@ -88,10 +88,7 @@ public class OuterObjectWithEnumProperty  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ParentWithNullable.java
index 68195c225086..b6b3f1edb025 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ParentWithNullable.java
@@ -158,10 +158,7 @@ public class ParentWithNullable  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Pet.java
index d077405a93c4..42faaa7ace11 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Pet.java
@@ -293,10 +293,7 @@ public class Pet  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index 1edaeef0d732..514ceb03827e 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -103,10 +103,7 @@ public class ReadOnlyFirst  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/SpecialModelName.java
index a3e316c705ba..138803023f45 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -81,10 +81,7 @@ public class SpecialModelName  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Tag.java
index d9254eb9e5ef..971923af58e3 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/Tag.java
@@ -103,10 +103,7 @@ public class Tag  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 0ac1a091d884..4978c3a1439c 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -116,10 +116,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/User.java
index 2ecc37e6e966..15e91cdeebb1 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-annotations/src/gen/java/org/openapitools/model/User.java
@@ -242,10 +242,7 @@ public class User  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index 6f096372f4d6..dc84c2b1c036 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -136,10 +136,7 @@ public class AdditionalPropertiesClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
index f14149d6db1d..dccfaf3e634b 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
@@ -103,10 +103,7 @@ public class AllOfWithSingleRef  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Animal.java
index d3aa5db7e23f..e6fb3c66667f 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Animal.java
@@ -117,10 +117,7 @@ public class Animal  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 3466ce989150..e22350a17ac9 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -99,10 +99,7 @@ public class ArrayOfArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index 914c0e25ac8a..da8944cd0b4f 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -99,10 +99,7 @@ public class ArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ArrayTest.java
index 35f7104b49b3..dfcb156fd5ab 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -177,10 +177,7 @@ public class ArrayTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Capitalization.java
index 2cc7bb63efe5..a2d5c526c1d3 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Capitalization.java
@@ -195,10 +195,7 @@ public class Capitalization  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Cat.java
index 8b780ddca5e1..f79c10eb2285 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Cat.java
@@ -91,10 +91,7 @@ public class Cat extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Category.java
index d80a77d1fdb1..c29538b8d944 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Category.java
@@ -109,10 +109,7 @@ public class Category  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ChildWithNullable.java
index 522b0e34a3d9..5ad307b4e337 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ChildWithNullable.java
@@ -83,10 +83,7 @@ public class ChildWithNullable extends ParentWithNullable implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ClassModel.java
index b7391f8551cd..fa5a3cf9dbe5 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ClassModel.java
@@ -81,10 +81,7 @@ public class ClassModel  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Client.java
index c28c06e59f5b..cef8fce2ccdf 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Client.java
@@ -79,10 +79,7 @@ public class Client  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/DeprecatedObject.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/DeprecatedObject.java
index 2e7fbc8c6e6d..467dabfa3855 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/DeprecatedObject.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/DeprecatedObject.java
@@ -79,10 +79,7 @@ public class DeprecatedObject  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Dog.java
index ae5c3bb9ff8a..0d30d2ea4c89 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Dog.java
@@ -91,10 +91,7 @@ public class Dog extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/EnumArrays.java
index 4b682c39e840..669d665c0c54 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -215,10 +215,7 @@ public class EnumArrays  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/EnumTest.java
index 32f1e4fd1c6b..15cf0b1fe4ef 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/EnumTest.java
@@ -441,10 +441,7 @@ public class EnumTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
index 4023ba4198ac..ee91f3c7cbae 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
@@ -122,10 +122,7 @@ public class FakeBigDecimalMap200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java
index f28b39943968..9255a417df30 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java
@@ -245,10 +245,7 @@ public class FakeTestsDefaultsDefaultResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index 7cb38f74e9bc..ca7263cfcdeb 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -122,10 +122,7 @@ public class FileSchemaTestClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Foo.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Foo.java
index 6ac0606fe888..8c7f87511bfd 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Foo.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Foo.java
@@ -79,10 +79,7 @@ public class Foo  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
index 6739aab8d82a..7615b0f4383c 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
@@ -81,10 +81,7 @@ public class FooGetDefaultResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FormatTest.java
index 367584928408..f9c0e83f4401 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/FormatTest.java
@@ -456,10 +456,7 @@ public class FormatTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index 2c913ab4e3e4..1a3b30d4e847 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -103,10 +103,7 @@ public class HasOnlyReadOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/HealthCheckResult.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/HealthCheckResult.java
index 39a6a968a6a7..a9198513cba0 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/HealthCheckResult.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/HealthCheckResult.java
@@ -82,10 +82,7 @@ public class HealthCheckResult  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/MapTest.java
index 87f0acc925a1..76e95abe8217 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/MapTest.java
@@ -261,10 +261,7 @@ public class MapTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 119b1ce9c10d..ec85046b6d92 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -146,10 +146,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Model200Response.java
index a6a1447f9bc5..202521432159 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Model200Response.java
@@ -105,10 +105,7 @@ public class Model200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ModelApiResponse.java
index 5f43c909ea2f..95105aca3855 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -126,10 +126,7 @@ public class ModelApiResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ModelFile.java
index fc75f3943483..cb45eaf69784 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ModelFile.java
@@ -83,10 +83,7 @@ public class ModelFile  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ModelList.java
index 3944d046aeb9..75306f383d9e 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ModelList.java
@@ -80,10 +80,7 @@ public class ModelList  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ModelReturn.java
index cf0d99ba26d1..a0c9e9f204d0 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -82,10 +82,7 @@ public class ModelReturn  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Name.java
index aa400ac0d469..9517fc475d25 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Name.java
@@ -157,10 +157,7 @@ public class Name  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/NullableClass.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/NullableClass.java
index 93e5b9d63988..0741d3a7e144 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/NullableClass.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/NullableClass.java
@@ -459,10 +459,7 @@ public class NullableClass extends HashMap<String, Object> implements Serializab
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/NumberOnly.java
index e00fa02bff20..61ee849b78b2 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -80,10 +80,7 @@ public class NumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
index aaf5cc64e26d..82fe3c941611 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
@@ -169,10 +169,7 @@ public class ObjectWithDeprecatedFields  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Order.java
index c13a3af6fd51..7c930a9c8960 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/OuterComposite.java
index 5b3a07e16f7c..67a1bf4d7ac7 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -126,10 +126,7 @@ public class OuterComposite  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
index c454b009be3b..c72249aa6875 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
@@ -87,10 +87,7 @@ public class OuterObjectWithEnumProperty  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ParentWithNullable.java
index 398870fa74ae..8cb1a1f38ff1 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ParentWithNullable.java
@@ -157,10 +157,7 @@ public class ParentWithNullable  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Pet.java
index 96297b3e56e3..ac71462dfa06 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Pet.java
@@ -292,10 +292,7 @@ public class Pet  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index ae994186718d..17aebcbcc005 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -102,10 +102,7 @@ public class ReadOnlyFirst  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/SpecialModelName.java
index ee5efd8d86f7..e80a8f099b4f 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -80,10 +80,7 @@ public class SpecialModelName  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Tag.java
index 9459ce99b6d7..3693c3a47504 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 13a6614c5a95..209d31e6f5f9 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -115,10 +115,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/User.java
index 8a55101c6e71..2a2b24886402 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations-jakarta/src/gen/java/org/openapitools/model/User.java
@@ -241,10 +241,7 @@ public class User  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index cd9ef2f7ec89..9483e74142e1 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -136,10 +136,7 @@ public class AdditionalPropertiesClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
index d9815dcf64b4..80fb1d336e00 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
@@ -103,10 +103,7 @@ public class AllOfWithSingleRef  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Animal.java
index 6e21f5aae534..6de117612f00 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Animal.java
@@ -117,10 +117,7 @@ public class Animal  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 0236adb4e368..d349c0ad63c6 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -99,10 +99,7 @@ public class ArrayOfArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index 268a16c822ec..fd010cdfabd5 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -99,10 +99,7 @@ public class ArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ArrayTest.java
index f180517150d4..ac59c613e90a 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -177,10 +177,7 @@ public class ArrayTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Capitalization.java
index 0a1f22789099..33acb5a72a32 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Capitalization.java
@@ -195,10 +195,7 @@ public class Capitalization  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Cat.java
index c0b341c3d582..d476872ae437 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Cat.java
@@ -91,10 +91,7 @@ public class Cat extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Category.java
index 91da0e0e0c56..835ded5a21c8 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Category.java
@@ -109,10 +109,7 @@ public class Category  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ChildWithNullable.java
index 71383f4e7b23..7b4661f30961 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ChildWithNullable.java
@@ -83,10 +83,7 @@ public class ChildWithNullable extends ParentWithNullable implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ClassModel.java
index b143fa32b88a..d2e1bbfd53e3 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ClassModel.java
@@ -81,10 +81,7 @@ public class ClassModel  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Client.java
index e1aed81a0c11..c8a766388503 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Client.java
@@ -79,10 +79,7 @@ public class Client  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/DeprecatedObject.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/DeprecatedObject.java
index 680915a2ae7b..2cbd0c2fa543 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/DeprecatedObject.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/DeprecatedObject.java
@@ -79,10 +79,7 @@ public class DeprecatedObject  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Dog.java
index f951068119d6..927edd57e437 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Dog.java
@@ -91,10 +91,7 @@ public class Dog extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/EnumArrays.java
index ba4a20b3b4e6..d3af0d9b4bd6 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -215,10 +215,7 @@ public class EnumArrays  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/EnumTest.java
index 4a722e750128..93bcdb6a837f 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/EnumTest.java
@@ -441,10 +441,7 @@ public class EnumTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
index fc535c157c25..9ccb9cdbfbfe 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
@@ -122,10 +122,7 @@ public class FakeBigDecimalMap200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java
index e05f285171d0..b97f4acc7550 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java
@@ -245,10 +245,7 @@ public class FakeTestsDefaultsDefaultResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index 0ec741ad56fb..a39523054f36 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -122,10 +122,7 @@ public class FileSchemaTestClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Foo.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Foo.java
index 3b341756ad8e..ef6a34f6afda 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Foo.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Foo.java
@@ -79,10 +79,7 @@ public class Foo  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
index a60670d2859b..bcbe26e51268 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
@@ -81,10 +81,7 @@ public class FooGetDefaultResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FormatTest.java
index 27f34499514d..8036fa23b4cb 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/FormatTest.java
@@ -456,10 +456,7 @@ public class FormatTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index d3fa10384d93..4042dd24275e 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -103,10 +103,7 @@ public class HasOnlyReadOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/HealthCheckResult.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/HealthCheckResult.java
index 4e55dc3e1e32..2b3f4c8eb769 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/HealthCheckResult.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/HealthCheckResult.java
@@ -82,10 +82,7 @@ public class HealthCheckResult  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/MapTest.java
index 6dd8a740b8bb..45681bad5171 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/MapTest.java
@@ -261,10 +261,7 @@ public class MapTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 1d6241754128..e068bd6719cf 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -146,10 +146,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Model200Response.java
index 7e84cb5d019c..0023c84f805a 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Model200Response.java
@@ -105,10 +105,7 @@ public class Model200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ModelApiResponse.java
index 6dd10206d3e2..ad2d0ed9c0cd 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -126,10 +126,7 @@ public class ModelApiResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ModelFile.java
index 7b4925892042..3d11fac9738a 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ModelFile.java
@@ -83,10 +83,7 @@ public class ModelFile  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ModelList.java
index dc8a3c10fdcd..e8df137440a4 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ModelList.java
@@ -80,10 +80,7 @@ public class ModelList  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ModelReturn.java
index 2dac9b66e516..cbe047ac5bf2 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -82,10 +82,7 @@ public class ModelReturn  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Name.java
index 2711e56d953d..b2235843fc08 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Name.java
@@ -157,10 +157,7 @@ public class Name  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/NullableClass.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/NullableClass.java
index 064d4c95a266..99f3f0e52143 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/NullableClass.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/NullableClass.java
@@ -459,10 +459,7 @@ public class NullableClass extends HashMap<String, Object> implements Serializab
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/NumberOnly.java
index 89e82e4d559d..46290265bfce 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -80,10 +80,7 @@ public class NumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
index 3772a64e497a..b25839f7e4d8 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
@@ -169,10 +169,7 @@ public class ObjectWithDeprecatedFields  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Order.java
index 76decc3b518c..ab99cd953ed0 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/OuterComposite.java
index 3b35ae496042..774c1a0bc82d 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -126,10 +126,7 @@ public class OuterComposite  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
index c08c14566ebe..e37413f32428 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
@@ -87,10 +87,7 @@ public class OuterObjectWithEnumProperty  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ParentWithNullable.java
index 2d12fd597999..7add7dbf1887 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ParentWithNullable.java
@@ -157,10 +157,7 @@ public class ParentWithNullable  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Pet.java
index 1dc0a9e70b60..92e7a8d49e0e 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Pet.java
@@ -292,10 +292,7 @@ public class Pet  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index 4f09c8b805d4..c05efea31468 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -102,10 +102,7 @@ public class ReadOnlyFirst  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/SpecialModelName.java
index 6308dff7e109..b41d24033ebe 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -80,10 +80,7 @@ public class SpecialModelName  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Tag.java
index ed7cbf28860c..da6e6d79aa4b 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
index a7883ac5b4a8..41e030befb5c 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -115,10 +115,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/User.java
index 47d5d1197172..8dd0d4632999 100644
--- a/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-spec-swagger-v3-annotations/src/gen/java/org/openapitools/model/User.java
@@ -241,10 +241,7 @@ public class User  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index ba4bccc292a9..c2b8822982e6 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -152,10 +152,7 @@ public class AdditionalPropertiesClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
index 2443cf40835c..099eb4f37af7 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
@@ -119,10 +119,7 @@ public class AllOfWithSingleRef  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Animal.java
index 36dea4b5d3a7..b8cbf7f05361 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Animal.java
@@ -133,10 +133,7 @@ public class Animal  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index bcf105f2c81f..e2d459186274 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -114,10 +114,7 @@ public class ArrayOfArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index 1dde813b6f2a..3f116aedf097 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -114,10 +114,7 @@ public class ArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ArrayTest.java
index 5d228ca55f34..ab67d592fa36 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -194,10 +194,7 @@ public class ArrayTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Capitalization.java
index e06851671b06..262a41595a12 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Capitalization.java
@@ -215,10 +215,7 @@ public class Capitalization  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Cat.java
index ad2d7fb3ebc5..57f3e026e645 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Cat.java
@@ -106,10 +106,7 @@ public class Cat extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Category.java
index f3f15a09a80b..f3a7dd1a7d59 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Category.java
@@ -125,10 +125,7 @@ public class Category  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ChildWithNullable.java
index 4a3ed977f79c..01811a190d2f 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ChildWithNullable.java
@@ -98,10 +98,7 @@ public class ChildWithNullable extends ParentWithNullable implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ClassModel.java
index 347b115fa889..910f3cd7afd6 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ClassModel.java
@@ -96,10 +96,7 @@ public class ClassModel  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Client.java
index 4b88e608f3e9..13aa1f2e1406 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Client.java
@@ -94,10 +94,7 @@ public class Client  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/DeprecatedObject.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/DeprecatedObject.java
index 5584680e754c..1193af70b558 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/DeprecatedObject.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/DeprecatedObject.java
@@ -94,10 +94,7 @@ public class DeprecatedObject  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Dog.java
index 8c0469b74763..e5d3661b92a1 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Dog.java
@@ -106,10 +106,7 @@ public class Dog extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/EnumArrays.java
index ef9a1eedcc5d..387ee34a90f0 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -235,10 +235,7 @@ public enum ArrayEnumEnum {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/EnumTest.java
index 9307846412d3..7f9211f74795 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/EnumTest.java
@@ -471,10 +471,7 @@ public enum EnumNumberEnum {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
index 16f0f2a901db..6ef0fcf44922 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
@@ -138,10 +138,7 @@ public class FakeBigDecimalMap200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java
index 8e7ccb3bd472..7fd982a31a46 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java
@@ -267,10 +267,7 @@ public enum IntegerEnumInlineEnum {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index 5d21e7b6789a..3aff9e79cda2 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -138,10 +138,7 @@ public class FileSchemaTestClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Foo.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Foo.java
index afb661b6599e..c8f29e31fa27 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Foo.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Foo.java
@@ -94,10 +94,7 @@ public class Foo  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
index 66c85c7523b8..a2f756c2a5b8 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
@@ -96,10 +96,7 @@ public class FooGetDefaultResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FormatTest.java
index fad9694fcf65..2c947c72b4be 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/FormatTest.java
@@ -486,10 +486,7 @@ public class FormatTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index c714f9f2bcf2..e251c7776041 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -119,10 +119,7 @@ public class HasOnlyReadOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/HealthCheckResult.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/HealthCheckResult.java
index fd039805b628..a6f275e87b1f 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/HealthCheckResult.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/HealthCheckResult.java
@@ -97,10 +97,7 @@ public class HealthCheckResult  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/MapTest.java
index 13e4c477c3d5..1ea3457e1ad5 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/MapTest.java
@@ -281,10 +281,7 @@ public enum InnerEnum {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 2265cc687b04..7522e3167aac 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -163,10 +163,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Model200Response.java
index 6dbdf1667968..c5f83dddf27a 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Model200Response.java
@@ -121,10 +121,7 @@ public class Model200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ModelApiResponse.java
index 9c0a8f1d1725..eb90e212cbd3 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -143,10 +143,7 @@ public class ModelApiResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ModelFile.java
index c38d79262cf0..fde3048d4c57 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ModelFile.java
@@ -98,10 +98,7 @@ public class ModelFile  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ModelList.java
index 3b24196de562..d243ac026592 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ModelList.java
@@ -95,10 +95,7 @@ public class ModelList  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ModelReturn.java
index eddb0b82f855..501b7abb5461 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -97,10 +97,7 @@ public class ModelReturn  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Name.java
index fa7994ee1c79..327e2984d600 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Name.java
@@ -175,10 +175,7 @@ public class Name  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/NullableClass.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/NullableClass.java
index 79431192afcc..615a49942bbd 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/NullableClass.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/NullableClass.java
@@ -485,10 +485,7 @@ public class NullableClass extends HashMap<String, Object> implements Serializab
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/NumberOnly.java
index 92d200b2fd47..ebb43edb2ffa 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -95,10 +95,7 @@ public class NumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
index 54d92e77df40..b5078d53e937 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
@@ -187,10 +187,7 @@ public class ObjectWithDeprecatedFields  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Order.java
index 085bdc9d428d..289a9d519980 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Order.java
@@ -265,10 +265,7 @@ public enum StatusEnum {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/OuterComposite.java
index 96fbe7cfb2fe..b349a4e87e67 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -143,10 +143,7 @@ public class OuterComposite  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
index bcaff5d54637..5e7ebfdb4108 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
@@ -102,10 +102,7 @@ public class OuterObjectWithEnumProperty  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ParentWithNullable.java
index 2bd7dfaa952e..b7d3f5d8842b 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ParentWithNullable.java
@@ -175,10 +175,7 @@ public enum TypeEnum {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Pet.java
index c08786d22037..e09f21f4f2a6 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Pet.java
@@ -314,10 +314,7 @@ public enum StatusEnum {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index aee8cde04097..ae347f82db32 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -118,10 +118,7 @@ public class ReadOnlyFirst  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/SpecialModelName.java
index da233e14e0f0..73b9dc36eeb4 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -95,10 +95,7 @@ public class SpecialModelName  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Tag.java
index af5d5e548c50..4ee12805c465 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/Tag.java
@@ -118,10 +118,7 @@ public class Tag  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 0ac07b8c6bc6..3a0a88106bc8 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -130,10 +130,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/User.java
index bc02e603f256..1699d398e8e4 100644
--- a/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-spec-withxml/src/gen/java/org/openapitools/model/User.java
@@ -263,10 +263,7 @@ public class User  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index 5ea57d05d6c3..4b422811f2d0 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -137,10 +137,7 @@ public class AdditionalPropertiesClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
index f6b3ed24a3a2..d2c4fe08862a 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
@@ -104,10 +104,7 @@ public class AllOfWithSingleRef  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Animal.java
index 147806907874..e58eadc74279 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Animal.java
@@ -118,10 +118,7 @@ public class Animal  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index f4410ea7fa6d..7e9590f48d21 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -100,10 +100,7 @@ public class ArrayOfArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index 998607f2662b..9f16ed7c02ee 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -100,10 +100,7 @@ public class ArrayOfNumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ArrayTest.java
index 9255ad844c8c..970dba759cc5 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -178,10 +178,7 @@ public class ArrayTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Capitalization.java
index e1451b75fa59..b15c2d95c196 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Capitalization.java
@@ -196,10 +196,7 @@ public class Capitalization  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Cat.java
index 459ccab73465..03c6b71e923c 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Cat.java
@@ -92,10 +92,7 @@ public class Cat extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Category.java
index b75f24e99f71..605bffc8b0f8 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Category.java
@@ -110,10 +110,7 @@ public class Category  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ChildWithNullable.java
index 3c30e7d7b0a8..6f074c7f3ce2 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ChildWithNullable.java
@@ -84,10 +84,7 @@ public class ChildWithNullable extends ParentWithNullable implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ClassModel.java
index be44a0dff5b4..a3a78265ab94 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ClassModel.java
@@ -82,10 +82,7 @@ public class ClassModel  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Client.java
index 3a9f1b451e09..4a8739cd5b85 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Client.java
@@ -80,10 +80,7 @@ public class Client  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/DeprecatedObject.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/DeprecatedObject.java
index 5d7d01991586..b5992a2c4c76 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/DeprecatedObject.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/DeprecatedObject.java
@@ -80,10 +80,7 @@ public class DeprecatedObject  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Dog.java
index b3c5f3ea573c..2e1b00f142da 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Dog.java
@@ -92,10 +92,7 @@ public class Dog extends Animal implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/EnumArrays.java
index 498bb029ccd5..9c92f0e261fd 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -216,10 +216,7 @@ public class EnumArrays  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/EnumTest.java
index d80f8178d14b..a36635f54878 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/EnumTest.java
@@ -442,10 +442,7 @@ public class EnumTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
index 533ee1fb5d60..9c431bfdc2c4 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
@@ -123,10 +123,7 @@ public class FakeBigDecimalMap200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java
index 204519afdfbe..b7085a59be07 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FakeTestsDefaultsDefaultResponse.java
@@ -246,10 +246,7 @@ public class FakeTestsDefaultsDefaultResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index bf6e2175c72d..781dda2f0174 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -123,10 +123,7 @@ public class FileSchemaTestClass  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Foo.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Foo.java
index f6be04545e9f..7ee394dbeeea 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Foo.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Foo.java
@@ -80,10 +80,7 @@ public class Foo  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
index 524ef54678cf..c7416c5772d7 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
@@ -82,10 +82,7 @@ public class FooGetDefaultResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FormatTest.java
index 700e77c1a755..5bd565258905 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/FormatTest.java
@@ -457,10 +457,7 @@ public class FormatTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index bfc989a95b55..4d5dc2f4f23e 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/HealthCheckResult.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/HealthCheckResult.java
index c21ecc8bfd93..a6c0d15e5f19 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/HealthCheckResult.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/HealthCheckResult.java
@@ -83,10 +83,7 @@ public class HealthCheckResult  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/MapTest.java
index ff24115551ab..d3fbb16a45b1 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/MapTest.java
@@ -262,10 +262,7 @@ public class MapTest  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 74d951cd97a2..bfb433e78efb 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -147,10 +147,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass  implements Serializabl
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Model200Response.java
index 295d0d5f530a..c3384310e878 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Model200Response.java
@@ -106,10 +106,7 @@ public class Model200Response  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ModelApiResponse.java
index 3c3052b732e1..72e2174ebc93 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -127,10 +127,7 @@ public class ModelApiResponse  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ModelFile.java
index 9627e5c2cb9c..cabe1925f185 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ModelFile.java
@@ -84,10 +84,7 @@ public class ModelFile  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ModelList.java
index 153f3220d19d..8190229f8636 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ModelList.java
@@ -81,10 +81,7 @@ public class ModelList  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ModelReturn.java
index 88f52e904609..71e0ce2a996b 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -83,10 +83,7 @@ public class ModelReturn  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Name.java
index c737650a25ff..d6444623f666 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Name.java
@@ -158,10 +158,7 @@ public class Name  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/NullableClass.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/NullableClass.java
index 49208a56fc3d..27f71a7b7d6c 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/NullableClass.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/NullableClass.java
@@ -460,10 +460,7 @@ public class NullableClass extends HashMap<String, Object> implements Serializab
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/NumberOnly.java
index 199ab5aa0422..a637bddab623 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -81,10 +81,7 @@ public class NumberOnly  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
index 425c5ec4a59b..36fa9c0a26ef 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
@@ -170,10 +170,7 @@ public class ObjectWithDeprecatedFields  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Order.java
index 4f972f377999..45a86c201672 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Order.java
@@ -244,10 +244,7 @@ public class Order  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/OuterComposite.java
index 9ad100cb4ece..9f15c8ba1f7a 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -127,10 +127,7 @@ public class OuterComposite  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
index 4318bc74a83a..97e7dd3f49ce 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
@@ -88,10 +88,7 @@ public class OuterObjectWithEnumProperty  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ParentWithNullable.java
index 68195c225086..b6b3f1edb025 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ParentWithNullable.java
@@ -158,10 +158,7 @@ public class ParentWithNullable  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Pet.java
index d077405a93c4..42faaa7ace11 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Pet.java
@@ -293,10 +293,7 @@ public class Pet  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index 1edaeef0d732..514ceb03827e 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -103,10 +103,7 @@ public class ReadOnlyFirst  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/SpecialModelName.java
index a3e316c705ba..138803023f45 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -81,10 +81,7 @@ public class SpecialModelName  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Tag.java
index d9254eb9e5ef..971923af58e3 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/Tag.java
@@ -103,10 +103,7 @@ public class Tag  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 0ac1a091d884..4978c3a1439c 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -116,10 +116,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/User.java
index 2ecc37e6e966..15e91cdeebb1 100644
--- a/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs-spec/src/gen/java/org/openapitools/model/User.java
@@ -242,10 +242,7 @@ public class User  implements Serializable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index a9feb83b6c29..0a55eee05f75 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -89,10 +89,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
index b0199870d49d..25f681048178 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -90,10 +90,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index ad35bb99f3bd..126a9f8ff313 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -89,10 +89,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index 032ab17040ca..bece3586f2a7 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -425,10 +425,7 @@ public class AdditionalPropertiesClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 581702b1cec9..230c7ccc2dae 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -89,10 +89,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
index 4be86bf79feb..8e99333a28f7 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -90,10 +90,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
index ee635689b9d4..b9e45aece8bd 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -89,10 +89,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
index c1c7e5faf4d4..572b5c561dd9 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -89,10 +89,7 @@ public class AdditionalPropertiesString extends HashMap<String, String>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Animal.java
index fc89bd0d67bb..0294128e384d 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Animal.java
@@ -123,10 +123,7 @@ public class Animal   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 39d01b0ed8c3..ebf0177cf227 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -99,10 +99,7 @@ public class ArrayOfArrayOfNumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index c17cabc119a6..c3f5af823bfa 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -99,10 +99,7 @@ public class ArrayOfNumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ArrayTest.java
index 6683b776f353..9e19507410b1 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -169,10 +169,7 @@ public class ArrayTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/BigCat.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/BigCat.java
index d1ba2c385d88..3d6111ac3c9f 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/BigCat.java
@@ -128,10 +128,7 @@ public class BigCat extends Cat  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Capitalization.java
index 7ca5a13d911f..2806b5416bc7 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Capitalization.java
@@ -222,10 +222,7 @@ public class Capitalization   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Cat.java
index e6e62d1bc74d..78118e85fb4d 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Cat.java
@@ -88,10 +88,7 @@ public class Cat extends Animal  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Category.java
index 1d36b09d30af..8b05a1a68175 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Category.java
@@ -114,10 +114,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ClassModel.java
index 478bf3f95e7e..439464826bf7 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ClassModel.java
@@ -88,10 +88,7 @@ public class ClassModel   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Client.java
index 8f881c97371b..918a88b806b4 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Client.java
@@ -87,10 +87,7 @@ public class Client   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Dog.java
index d1fc941df4c7..936cbe12693e 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Dog.java
@@ -88,10 +88,7 @@ public class Dog extends Animal  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/EnumArrays.java
index f72eade5fa15..1bbd6342754b 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -196,10 +196,7 @@ public class EnumArrays   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/EnumTest.java
index dc58380cf66c..c6a1d992da23 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/EnumTest.java
@@ -342,10 +342,7 @@ public class EnumTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index 9ed8062dd343..50a92afa4892 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -126,10 +126,7 @@ public class FileSchemaTestClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/FormatTest.java
index dee35c482eeb..c5dbfd2332c2 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/FormatTest.java
@@ -453,10 +453,7 @@ public class FormatTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index 47a891575bda..af1ecd81421d 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -115,10 +115,7 @@ public class HasOnlyReadOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/MapTest.java
index 58a3a424d794..99e03adcec4f 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/MapTest.java
@@ -238,10 +238,7 @@ public class MapTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 5157e670f8ee..df811952325b 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -154,10 +154,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Model200Response.java
index 0d12263dbdf0..07781b9f11c4 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Model200Response.java
@@ -116,10 +116,7 @@ public class Model200Response   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ModelApiResponse.java
index 3dcf34bc5606..2d882ae5976b 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -142,10 +142,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ModelFile.java
index 1bc030e82c37..756b00b368ae 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ModelFile.java
@@ -89,10 +89,7 @@ public class ModelFile   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ModelList.java
index 5f26ea12bb17..effad15abf2d 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ModelList.java
@@ -88,10 +88,7 @@ public class ModelList   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ModelReturn.java
index 91d03d132be2..4306f84f09d0 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -89,10 +89,7 @@ public class ModelReturn   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Name.java
index 3231583b54d3..2698e7f41009 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Name.java
@@ -169,10 +169,7 @@ public class Name   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/NumberOnly.java
index 99dd85b36b77..077c0e1efd00 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -88,10 +88,7 @@ public class NumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Order.java
index d472ca78fc30..3da99fd3daec 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Order.java
@@ -261,10 +261,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/OuterComposite.java
index c68c6e264ed9..3ca574aa9f9a 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -142,10 +142,7 @@ public class OuterComposite   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Pet.java
index b956ce77f47c..76018769ca41 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Pet.java
@@ -285,10 +285,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index 0551515f6868..b3fd6e72e285 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -114,10 +114,7 @@ public class ReadOnlyFirst   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/SpecialModelName.java
index 2b7a9380cfe0..f2ebd89b472a 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -88,10 +88,7 @@ public class SpecialModelName   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Tag.java
index ecf2d1686a1d..40390efdfe55 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/Tag.java
@@ -114,10 +114,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/TypeHolderDefault.java
index 591996b7d45b..2ae60ec55476 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/TypeHolderDefault.java
@@ -207,10 +207,7 @@ public class TypeHolderDefault   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/TypeHolderExample.java
index 9e82984135b9..b096fd37eddf 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/TypeHolderExample.java
@@ -234,10 +234,7 @@ public class TypeHolderExample   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/User.java
index f58bb3499cbf..5426fb9dafb6 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/User.java
@@ -276,10 +276,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/XmlItem.java
index 13d5c0f0cbb3..2aed013b71a4 100644
--- a/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/jaxrs/jersey2-useTags/src/gen/java/org/openapitools/model/XmlItem.java
@@ -919,10 +919,7 @@ public class XmlItem   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index a9feb83b6c29..0a55eee05f75 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -89,10 +89,7 @@ public class AdditionalPropertiesAnyType extends HashMap<String, Object>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
index b0199870d49d..25f681048178 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -90,10 +90,7 @@ public class AdditionalPropertiesArray extends HashMap<String, List>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index ad35bb99f3bd..126a9f8ff313 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -89,10 +89,7 @@ public class AdditionalPropertiesBoolean extends HashMap<String, Boolean>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index 032ab17040ca..bece3586f2a7 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -425,10 +425,7 @@ public class AdditionalPropertiesClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 581702b1cec9..230c7ccc2dae 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -89,10 +89,7 @@ public class AdditionalPropertiesInteger extends HashMap<String, Integer>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
index 4be86bf79feb..8e99333a28f7 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -90,10 +90,7 @@ public class AdditionalPropertiesNumber extends HashMap<String, BigDecimal>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
index ee635689b9d4..b9e45aece8bd 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -89,10 +89,7 @@ public class AdditionalPropertiesObject extends HashMap<String, Map>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
index c1c7e5faf4d4..572b5c561dd9 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -89,10 +89,7 @@ public class AdditionalPropertiesString extends HashMap<String, String>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Animal.java
index fc89bd0d67bb..0294128e384d 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Animal.java
@@ -123,10 +123,7 @@ public class Animal   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 39d01b0ed8c3..ebf0177cf227 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -99,10 +99,7 @@ public class ArrayOfArrayOfNumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index c17cabc119a6..c3f5af823bfa 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -99,10 +99,7 @@ public class ArrayOfNumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ArrayTest.java
index 6683b776f353..9e19507410b1 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -169,10 +169,7 @@ public class ArrayTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/BigCat.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/BigCat.java
index d1ba2c385d88..3d6111ac3c9f 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/BigCat.java
@@ -128,10 +128,7 @@ public class BigCat extends Cat  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Capitalization.java
index 7ca5a13d911f..2806b5416bc7 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Capitalization.java
@@ -222,10 +222,7 @@ public class Capitalization   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Cat.java
index e6e62d1bc74d..78118e85fb4d 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Cat.java
@@ -88,10 +88,7 @@ public class Cat extends Animal  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Category.java
index 1d36b09d30af..8b05a1a68175 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Category.java
@@ -114,10 +114,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ClassModel.java
index 478bf3f95e7e..439464826bf7 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ClassModel.java
@@ -88,10 +88,7 @@ public class ClassModel   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Client.java
index 8f881c97371b..918a88b806b4 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Client.java
@@ -87,10 +87,7 @@ public class Client   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Dog.java
index d1fc941df4c7..936cbe12693e 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Dog.java
@@ -88,10 +88,7 @@ public class Dog extends Animal  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/EnumArrays.java
index f72eade5fa15..1bbd6342754b 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -196,10 +196,7 @@ public class EnumArrays   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/EnumTest.java
index dc58380cf66c..c6a1d992da23 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/EnumTest.java
@@ -342,10 +342,7 @@ public class EnumTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index 9ed8062dd343..50a92afa4892 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -126,10 +126,7 @@ public class FileSchemaTestClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/FormatTest.java
index dee35c482eeb..c5dbfd2332c2 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/FormatTest.java
@@ -453,10 +453,7 @@ public class FormatTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index 47a891575bda..af1ecd81421d 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -115,10 +115,7 @@ public class HasOnlyReadOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/MapTest.java
index 58a3a424d794..99e03adcec4f 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/MapTest.java
@@ -238,10 +238,7 @@ public class MapTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 5157e670f8ee..df811952325b 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -154,10 +154,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Model200Response.java
index 0d12263dbdf0..07781b9f11c4 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Model200Response.java
@@ -116,10 +116,7 @@ public class Model200Response   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ModelApiResponse.java
index 3dcf34bc5606..2d882ae5976b 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -142,10 +142,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ModelFile.java
index 1bc030e82c37..756b00b368ae 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ModelFile.java
@@ -89,10 +89,7 @@ public class ModelFile   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ModelList.java
index 5f26ea12bb17..effad15abf2d 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ModelList.java
@@ -88,10 +88,7 @@ public class ModelList   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ModelReturn.java
index 91d03d132be2..4306f84f09d0 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -89,10 +89,7 @@ public class ModelReturn   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Name.java
index 3231583b54d3..2698e7f41009 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Name.java
@@ -169,10 +169,7 @@ public class Name   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/NumberOnly.java
index 99dd85b36b77..077c0e1efd00 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -88,10 +88,7 @@ public class NumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Order.java
index d472ca78fc30..3da99fd3daec 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Order.java
@@ -261,10 +261,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/OuterComposite.java
index c68c6e264ed9..3ca574aa9f9a 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -142,10 +142,7 @@ public class OuterComposite   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Pet.java
index b956ce77f47c..76018769ca41 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Pet.java
@@ -285,10 +285,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index 0551515f6868..b3fd6e72e285 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -114,10 +114,7 @@ public class ReadOnlyFirst   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/SpecialModelName.java
index 2b7a9380cfe0..f2ebd89b472a 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -88,10 +88,7 @@ public class SpecialModelName   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Tag.java
index ecf2d1686a1d..40390efdfe55 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/Tag.java
@@ -114,10 +114,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/TypeHolderDefault.java
index 591996b7d45b..2ae60ec55476 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/TypeHolderDefault.java
@@ -207,10 +207,7 @@ public class TypeHolderDefault   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/TypeHolderExample.java
index 9e82984135b9..b096fd37eddf 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/TypeHolderExample.java
@@ -234,10 +234,7 @@ public class TypeHolderExample   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/User.java
index f58bb3499cbf..5426fb9dafb6 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/User.java
@@ -276,10 +276,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/XmlItem.java
index 13d5c0f0cbb3..2aed013b71a4 100644
--- a/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/jaxrs/jersey2/src/gen/java/org/openapitools/model/XmlItem.java
@@ -919,10 +919,7 @@ public class XmlItem   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
index ec8050186d52..9122ac8a2a43 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -131,10 +131,7 @@ public class AdditionalPropertiesClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
index 6c070e197347..ac89d5e071fb 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/AllOfWithSingleRef.java
@@ -115,10 +115,7 @@ public class AllOfWithSingleRef   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Animal.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Animal.java
index ddfe447083bf..584777e38497 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Animal.java
@@ -121,10 +121,7 @@ public class Animal   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 770318757847..73c52b6b4682 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -98,10 +98,7 @@ public class ArrayOfArrayOfNumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index 5de9327f86dc..23dc28c1fa69 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -98,10 +98,7 @@ public class ArrayOfNumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ArrayTest.java
index dce13036df42..910a1c838864 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -168,10 +168,7 @@ public class ArrayTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Capitalization.java
index 791f33cd026c..239bc11042bc 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Capitalization.java
@@ -221,10 +221,7 @@ public class Capitalization   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Cat.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Cat.java
index f3e5c0452ab1..b4049afbd8df 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Cat.java
@@ -87,10 +87,7 @@ public class Cat extends Animal  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Category.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Category.java
index 1347017ee7d8..2a3f2a0539f2 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Category.java
@@ -113,10 +113,7 @@ public class Category   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ChildWithNullable.java
index 7a676f815bca..5b7506dace25 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ChildWithNullable.java
@@ -88,10 +88,7 @@ public class ChildWithNullable extends ParentWithNullable  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ClassModel.java
index d2374f797809..9ca72eb9be95 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ClassModel.java
@@ -87,10 +87,7 @@ public class ClassModel   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Client.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Client.java
index 188561a465b3..1f43068fce0c 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Client.java
@@ -86,10 +86,7 @@ public class Client   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/DeprecatedObject.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/DeprecatedObject.java
index e07cc9a50108..abc891536630 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/DeprecatedObject.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/DeprecatedObject.java
@@ -86,10 +86,7 @@ public class DeprecatedObject   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Dog.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Dog.java
index 232a279dc6e4..7dd7e445c446 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Dog.java
@@ -87,10 +87,7 @@ public class Dog extends Animal  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/EnumArrays.java
index cd93815637b1..5a991dfbc0ca 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -195,10 +195,7 @@ public class EnumArrays   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/EnumTest.java
index 0cca96e5ffb6..a62cd33a4299 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/EnumTest.java
@@ -425,10 +425,7 @@ public class EnumTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
index 1977efa149af..46f4af250b61 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/FakeBigDecimalMap200Response.java
@@ -125,10 +125,7 @@ public class FakeBigDecimalMap200Response   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index 255a941617be..79676fe364eb 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -125,10 +125,7 @@ public class FileSchemaTestClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Foo.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Foo.java
index 4c1499c2f8b4..7e1c037086ba 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Foo.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Foo.java
@@ -86,10 +86,7 @@ public class Foo   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
index 3f116d98dfa5..abcbe5e50f6b 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/FooGetDefaultResponse.java
@@ -88,10 +88,7 @@ public class FooGetDefaultResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/FormatTest.java
index 7e4ccb0ba348..cb35f6154885 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/FormatTest.java
@@ -506,10 +506,7 @@ public class FormatTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
index 0de0de7cda8b..6e51806539b4 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -114,10 +114,7 @@ public class HasOnlyReadOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/HealthCheckResult.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/HealthCheckResult.java
index cc53e8615dc4..824920fa3ede 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/HealthCheckResult.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/HealthCheckResult.java
@@ -87,10 +87,7 @@ public class HealthCheckResult   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/MapTest.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/MapTest.java
index 1d55bd6a1c86..cf2392fbe858 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/MapTest.java
@@ -237,10 +237,7 @@ public class MapTest   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index c5fc270c9cc0..5714f11a4fc3 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -153,10 +153,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Model200Response.java
index c922dbff7aa1..fbbde33e8b4b 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Model200Response.java
@@ -115,10 +115,7 @@ public class Model200Response   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ModelApiResponse.java
index dc24de425535..7812f218f161 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ModelApiResponse.java
@@ -141,10 +141,7 @@ public class ModelApiResponse   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ModelFile.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ModelFile.java
index 778a7d28fae6..6a808f5726da 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ModelFile.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ModelFile.java
@@ -88,10 +88,7 @@ public class ModelFile   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ModelList.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ModelList.java
index a9a8e0f1a8e4..bd1467feb21a 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ModelList.java
@@ -87,10 +87,7 @@ public class ModelList   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ModelReturn.java
index 98bef7c8c819..da99f9b4dd0b 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ModelReturn.java
@@ -88,10 +88,7 @@ public class ModelReturn   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Name.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Name.java
index eb5a2cc20d13..3819eb6f2887 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Name.java
@@ -168,10 +168,7 @@ public class Name   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/NullableClass.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/NullableClass.java
index 132735fcae09..b4cd9f6254c8 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/NullableClass.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/NullableClass.java
@@ -438,10 +438,7 @@ public class NullableClass extends HashMap<String, Object>  {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/NumberOnly.java
index a84f8b6c60ab..3ff3e204229c 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/NumberOnly.java
@@ -87,10 +87,7 @@ public class NumberOnly   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
index 0bd7a663779a..523614c3a5c8 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ObjectWithDeprecatedFields.java
@@ -180,10 +180,7 @@ public class ObjectWithDeprecatedFields   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Order.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Order.java
index 60b97dbc33e2..239c4c020449 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Order.java
@@ -260,10 +260,7 @@ public class Order   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/OuterComposite.java
index 0ad3cfdda5e6..ebb9bab562cd 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/OuterComposite.java
@@ -141,10 +141,7 @@ public class OuterComposite   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
index 2b62be583800..07486df17bc8 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/OuterObjectWithEnumProperty.java
@@ -88,10 +88,7 @@ public class OuterObjectWithEnumProperty   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ParentWithNullable.java
index 8c79e42f4d6c..81e60e11890a 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ParentWithNullable.java
@@ -154,10 +154,7 @@ public class ParentWithNullable   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Pet.java
index 711908ebb44e..20437c6fa454 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Pet.java
@@ -284,10 +284,7 @@ public class Pet   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
index 0fc407d21006..2600e7fab78a 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/ReadOnlyFirst.java
@@ -113,10 +113,7 @@ public class ReadOnlyFirst   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/SpecialModelName.java
index 94c1dee5202b..ea170dbd3b33 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/SpecialModelName.java
@@ -87,10 +87,7 @@ public class SpecialModelName   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Tag.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Tag.java
index f018bebaa627..31ed8e8f8ca9 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/Tag.java
@@ -113,10 +113,7 @@ public class Tag   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
index 6db1976af65b..6fe594de5793 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequest.java
@@ -89,10 +89,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest extends HashMap<Strin
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/User.java b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/User.java
index 8f81964d02ba..e3187e0e301f 100644
--- a/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/jaxrs/jersey3/src/gen/java/org/openapitools/model/User.java
@@ -275,10 +275,7 @@ public class User   {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index 9bed3605a83a..df23b2e0518f 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index f99436d96a05..6455b1d28477 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index a0bd52301143..cf9ce0f5e925 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index a6be2fb360ac..3d7389bec4c9 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -415,10 +415,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index ce5fca38d97e..3bdc569be02e 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index 75b6411f9486..0848aa710a2e 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index 2f79b622e77d..129dd92b5337 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index a398997f37f3..143e46a8644e 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Animal.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Animal.java
index 60c1ec48fa73..24e08237647d 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Animal.java
@@ -126,10 +126,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index f03af73fd905..eeae40cafa74 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -89,10 +89,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 47cfb85cee87..1b5d034f4ac8 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -89,10 +89,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ArrayTest.java
index 994e26756e0e..5951b8f4f981 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ArrayTest.java
@@ -157,10 +157,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/BigCat.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/BigCat.java
index c6e52675065f..f94bf89317f0 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/BigCat.java
@@ -149,10 +149,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Capitalization.java
index 65e6a969342c..afedf33fe0ba 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Capitalization.java
@@ -201,10 +201,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Cat.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Cat.java
index ab5710d450e5..9612eb31c5c4 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Cat.java
@@ -112,10 +112,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Category.java
index e807ddd8289e..ecdf126c9eda 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Category.java
@@ -112,10 +112,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ChildWithNullable.java
index 3378761ed1e9..01cc7eb0462e 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ChildWithNullable.java
@@ -107,10 +107,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ClassModel.java
index 9f97de621a29..3b17108cd459 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ClassModel.java
@@ -77,10 +77,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Client.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Client.java
index ad6d1b9c0d99..7f3a323e6af1 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Client.java
@@ -76,10 +76,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ContainerDefaultValue.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ContainerDefaultValue.java
index de6eaef4c62f..2386137fecb5 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ContainerDefaultValue.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ContainerDefaultValue.java
@@ -213,10 +213,7 @@ public class ContainerDefaultValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Dog.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Dog.java
index acaff69d979a..36c65b313657 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Dog.java
@@ -104,10 +104,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/EnumArrays.java
index 6879efae982d..1c6836270e59 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/EnumArrays.java
@@ -184,10 +184,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/EnumTest.java
index b5583270684c..3d3b901e796d 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/EnumTest.java
@@ -335,10 +335,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/File.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/File.java
index 70b59bd54553..3c808c2564fd 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/File.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/File.java
@@ -77,10 +77,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index 2e4d091a2030..b1da5f0f051d 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -114,10 +114,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/FormatTest.java
index b5970a92765f..bce3371774c1 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/FormatTest.java
@@ -435,10 +435,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 7f88fb964a28..9e99407cc172 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -103,10 +103,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/MapTest.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/MapTest.java
index 1f4517b1d4d0..0df5143e02ae 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/MapTest.java
@@ -225,10 +225,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 1e69f24f03c5..a2b9f47bf9ca 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -142,10 +142,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Model200Response.java
index ff1f86102e2e..c750a0d6534e 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Model200Response.java
@@ -104,10 +104,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ModelApiResponse.java
index 435055a10a58..f4bc1158e557 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -128,10 +128,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ModelList.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ModelList.java
index 34f55886cc98..60a860c7e5a6 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ModelList.java
@@ -78,10 +78,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ModelReturn.java
index 50ef51c9cbf5..e1062706a03f 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ModelReturn.java
@@ -79,10 +79,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Name.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Name.java
index 5ed451ca3a24..1ac9b0316cfb 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Name.java
@@ -163,10 +163,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/NullableMapProperty.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/NullableMapProperty.java
index 7f51e3098f2a..c7d431471e4d 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/NullableMapProperty.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/NullableMapProperty.java
@@ -100,10 +100,7 @@ public class NullableMapProperty {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/NumberOnly.java
index ada5eb7bc169..24f388d18059 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/NumberOnly.java
@@ -77,10 +77,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Order.java
index d556a66ac5fc..a8a085046bed 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Order.java
@@ -242,10 +242,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/OuterComposite.java
index 0a9dd63af928..f33e0a655695 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/OuterComposite.java
@@ -127,10 +127,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ParentWithNullable.java
index b49d7563a96e..7c079520417f 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ParentWithNullable.java
@@ -160,10 +160,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Pet.java
index b856d9a3c914..5f1acaaec695 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Pet.java
@@ -285,10 +285,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index 31d7faf6874e..8ca5a82f9c01 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -101,10 +101,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
index ac5973a769b5..064c39c2d87e 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
@@ -151,10 +151,7 @@ public class ResponseObjectWithDifferentFieldNames {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/SpecialModelName.java
index 0e98f6caaae8..d4ab4718139c 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -78,10 +78,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Tag.java
index 10e80a133066..ece3f449fa18 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/Tag.java
@@ -101,10 +101,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 77977aa44e73..858ed5d043b1 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -204,10 +204,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/TypeHolderExample.java
index dc0d7259d244..c1d22cceb21c 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -230,10 +230,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/User.java
index eabdbbb318cc..1e26e2d0fc35 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/User.java
@@ -251,10 +251,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/XmlItem.java
index 4fa5151512af..bb65cd50c02f 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledExcp/src/main/java/org/openapitools/model/XmlItem.java
@@ -861,10 +861,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/spring-boot-nullable-set/src/main/java/org/openapitools/model/ObjectWithUniqueItems.java b/samples/server/petstore/spring-boot-nullable-set/src/main/java/org/openapitools/model/ObjectWithUniqueItems.java
index 361f367c25cf..f2e8ed721872 100644
--- a/samples/server/petstore/spring-boot-nullable-set/src/main/java/org/openapitools/model/ObjectWithUniqueItems.java
+++ b/samples/server/petstore/spring-boot-nullable-set/src/main/java/org/openapitools/model/ObjectWithUniqueItems.java
@@ -259,10 +259,7 @@ public class ObjectWithUniqueItems {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-api-response-examples/src/main/java/org/openapitools/model/Dog.java b/samples/server/petstore/springboot-api-response-examples/src/main/java/org/openapitools/model/Dog.java
index 003565c2313a..3f358e9580ce 100644
--- a/samples/server/petstore/springboot-api-response-examples/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/springboot-api-response-examples/src/main/java/org/openapitools/model/Dog.java
@@ -102,10 +102,7 @@ public class Dog {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-api-response-examples/src/main/java/org/openapitools/model/Error.java b/samples/server/petstore/springboot-api-response-examples/src/main/java/org/openapitools/model/Error.java
index 5eb7dda2a3a9..61a17f72af26 100644
--- a/samples/server/petstore/springboot-api-response-examples/src/main/java/org/openapitools/model/Error.java
+++ b/samples/server/petstore/springboot-api-response-examples/src/main/java/org/openapitools/model/Error.java
@@ -101,10 +101,7 @@ public class Error {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index e4a8f7ec2e51..1b9f780290a5 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index f0847f37f3f0..9b1f8010ca4d 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 9344d20f6ab6..1248b13ef242 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index bbc50ca97666..d080f0ad9fd3 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -402,10 +402,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index e89529f71f89..c27cfb099434 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index 0320f3172faa..aac0e9d84a64 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index 50cc3bf465b8..ba5b4d037d23 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index 430ee8458e2d..39f39353e6aa 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Animal.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Animal.java
index a622e1d76d1d..1718c0a91051 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Animal.java
@@ -126,10 +126,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 34ac7a960519..7b2cab3e5fcf 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -89,10 +89,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index dc0e0ea66857..e9e5da8316b5 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -89,10 +89,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayTest.java
index 7add49480fd5..fb8e9f6e83d3 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayTest.java
@@ -157,10 +157,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/BigCat.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/BigCat.java
index e39c7b33cf6d..9ca60d82553e 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/BigCat.java
@@ -149,10 +149,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Capitalization.java
index 27c4123a3bdb..c550cc0543f7 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Capitalization.java
@@ -201,10 +201,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Cat.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Cat.java
index d86f3fe2f22c..fd407bcaee17 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Cat.java
@@ -112,10 +112,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Category.java
index fd3a9c720b17..7cc547f94eb1 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Category.java
@@ -112,10 +112,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ChildWithNullable.java
index 591cda9c4c47..03d9017ffda6 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ChildWithNullable.java
@@ -94,10 +94,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ClassModel.java
index c896fe10d34e..bbcbb670a843 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ClassModel.java
@@ -77,10 +77,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Client.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Client.java
index 276ec84408c5..03da69e99ca2 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Client.java
@@ -76,10 +76,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ContainerDefaultValue.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ContainerDefaultValue.java
index e694c07aca46..21fe2cdea231 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ContainerDefaultValue.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ContainerDefaultValue.java
@@ -202,10 +202,7 @@ public class ContainerDefaultValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Dog.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Dog.java
index a2ce8b5d7a7f..37ce81693d73 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Dog.java
@@ -104,10 +104,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/EnumArrays.java
index 86a1e098043b..2e82d3d8de52 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/EnumArrays.java
@@ -184,10 +184,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/EnumTest.java
index 977c39268f8d..859d6fc1c1d9 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/EnumTest.java
@@ -335,10 +335,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/File.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/File.java
index 2af78da21937..78459e9be890 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/File.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/File.java
@@ -77,10 +77,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index a0c55af65aa5..9d82b8fde8da 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -114,10 +114,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/FormatTest.java
index 418edd70dad9..8743c0e4230c 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/FormatTest.java
@@ -435,10 +435,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 0a55fa24f312..c6ea38055cf4 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -103,10 +103,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/MapTest.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/MapTest.java
index 5bd730378a75..ff4aadfa9e0f 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/MapTest.java
@@ -225,10 +225,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index b1b19b9908e1..0b0f33e3a468 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -142,10 +142,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Model200Response.java
index f9a260f33577..9702a1a004d1 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Model200Response.java
@@ -104,10 +104,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ModelApiResponse.java
index caa384678563..9cf059def20f 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -128,10 +128,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ModelList.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ModelList.java
index 7a221e3f4f38..3cc15aa19396 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ModelList.java
@@ -78,10 +78,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ModelReturn.java
index 3c10eb3f929b..075f319abe4d 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ModelReturn.java
@@ -79,10 +79,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Name.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Name.java
index 86008537acdb..c37cb0b5c228 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Name.java
@@ -163,10 +163,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/NullableMapProperty.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/NullableMapProperty.java
index 1c21064ad4de..fcb0edf1b593 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/NullableMapProperty.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/NullableMapProperty.java
@@ -87,10 +87,7 @@ public class NullableMapProperty {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/NumberOnly.java
index 768528e374c0..fa196d4af194 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/NumberOnly.java
@@ -77,10 +77,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Order.java
index 1b9fd0f22fb5..12d182b555f3 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Order.java
@@ -242,10 +242,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/OuterComposite.java
index 70912b3e1fd9..8f9084d82490 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/OuterComposite.java
@@ -127,10 +127,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ParentWithNullable.java
index 7945cba3fd50..b8e2422d81f9 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ParentWithNullable.java
@@ -147,10 +147,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Pet.java
index 002e53433996..ace4c240a67a 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Pet.java
@@ -285,10 +285,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index 75a57d80debe..04224bbc6096 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -101,10 +101,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
index 302dd2c91b01..661ab3f6a788 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
@@ -151,10 +151,7 @@ public class ResponseObjectWithDifferentFieldNames {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/SpecialModelName.java
index a4d83962287b..1706685dc9d9 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -78,10 +78,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Tag.java
index bd3e81b72a73..d6df673b64fd 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Tag.java
@@ -101,10 +101,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 9da9578dac89..47801ca61574 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -204,10 +204,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/TypeHolderExample.java
index 5a2d6e08b42e..c4d9cd9bf862 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -230,10 +230,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/User.java
index d0a74e43e466..54a37a4adb3c 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/User.java
@@ -251,10 +251,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/XmlItem.java
index d7dafd3fd772..072e0627d951 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/XmlItem.java
@@ -861,10 +861,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index bc9d82f06cc7..e9dd14f56239 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index a8a7b7c8709b..3615592aa420 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 9d4c0fd881f3..4002fe1cafc8 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index aceb2af0774a..2bb0e8bb4150 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -416,10 +416,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 4597109b6725..a1585b57526f 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index af9d9162747b..bf22d701b5e4 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index ecc59fe68c20..a9ad3cde1aaf 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index 7fcf1ce9d1ce..1311e77bd226 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Animal.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Animal.java
index 7f01983b4318..f1ec67972a65 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Animal.java
@@ -127,10 +127,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ba491560f22f..895f299988a1 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index d6dcf8043a8b..e7ce23c89bbe 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayTest.java
index 62370de480a6..513e4803a07e 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayTest.java
@@ -158,10 +158,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/BigCat.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/BigCat.java
index d4b1411684ba..77dff7865947 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/BigCat.java
@@ -150,10 +150,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Capitalization.java
index 41a27fce3ffa..9d852cbdd084 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Capitalization.java
@@ -202,10 +202,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Cat.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Cat.java
index 3f3db574df2c..6e6ab302f94f 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Cat.java
@@ -113,10 +113,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Category.java
index af18144f0fe0..90617a6ae32c 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Category.java
@@ -113,10 +113,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ChildWithNullable.java
index 52f9ddb03ccd..1851fdfee2bb 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ChildWithNullable.java
@@ -108,10 +108,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ClassModel.java
index 25a586388b8d..fd544e5df23b 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ClassModel.java
@@ -78,10 +78,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Client.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Client.java
index 4a8c8790cdef..7aeec07e4f3a 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Client.java
@@ -77,10 +77,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ContainerDefaultValue.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ContainerDefaultValue.java
index e6ea6bc5cf1c..54bb741071ef 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ContainerDefaultValue.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ContainerDefaultValue.java
@@ -214,10 +214,7 @@ public class ContainerDefaultValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Dog.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Dog.java
index f6c867a3dc25..0c58588e64ab 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Dog.java
@@ -105,10 +105,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/EnumArrays.java
index 6056c1ec1a1c..51bc8303094b 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/EnumArrays.java
@@ -185,10 +185,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/EnumTest.java
index e9d55788aadd..212f34aff977 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/EnumTest.java
@@ -336,10 +336,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/File.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/File.java
index 82a6b3f27463..78c59285275a 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/File.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/File.java
@@ -78,10 +78,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index a8b779ea8438..5b4e1753fdbe 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -115,10 +115,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/FormatTest.java
index 59e61e9e830f..967fec0da07b 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/FormatTest.java
@@ -436,10 +436,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 6397fd3ecf8e..e63ae315a3e1 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/MapTest.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/MapTest.java
index 9f5a2fa62182..942e32302829 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/MapTest.java
@@ -226,10 +226,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index efe2e655cc91..3bd85bd2cb19 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -143,10 +143,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Model200Response.java
index e22bc05d5226..a72cfadef665 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Model200Response.java
@@ -105,10 +105,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ModelApiResponse.java
index 73f04a6c18c1..9c6b66e2f48d 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ModelList.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ModelList.java
index c51842058780..80fdc758baa0 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ModelList.java
@@ -79,10 +79,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ModelReturn.java
index a7566970d26c..dca7af0ce9a4 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ModelReturn.java
@@ -80,10 +80,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Name.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Name.java
index f20b913bbc5e..f44b3c0451c9 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Name.java
@@ -164,10 +164,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/NullableMapProperty.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/NullableMapProperty.java
index 9ee932742ca7..bcc5f2a798bc 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/NullableMapProperty.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/NullableMapProperty.java
@@ -101,10 +101,7 @@ public class NullableMapProperty {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/NumberOnly.java
index 25baacd0fd41..09215d0986d9 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/NumberOnly.java
@@ -78,10 +78,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Order.java
index 41e0199f9487..e91482f5fd5d 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/OuterComposite.java
index dbe72f1de977..6c2522771275 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/OuterComposite.java
@@ -128,10 +128,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ParentWithNullable.java
index f5413e1cfd15..a812b63cc916 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ParentWithNullable.java
@@ -161,10 +161,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Pet.java
index d0385e65b479..b7ce9bec70a6 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Pet.java
@@ -286,10 +286,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index cbbdd596a94b..fe30f5929587 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -102,10 +102,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
index cf4798f27b61..79bbf112b64c 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
@@ -152,10 +152,7 @@ public class ResponseObjectWithDifferentFieldNames {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/SpecialModelName.java
index 2fdee9f5cbd4..81c0eda3fd90 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -79,10 +79,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Tag.java
index 67902d5a856f..b5386348fb16 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 984e3b84da47..4bfb01e8abcd 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -205,10 +205,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/TypeHolderExample.java
index c91d9f02c756..24392490e464 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -231,10 +231,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/User.java
index 06eb7e7feca4..fe12d1abb8c3 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/XmlItem.java
index 4fd02655a44e..aa2acf368944 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/XmlItem.java
@@ -862,10 +862,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index bc9d82f06cc7..e9dd14f56239 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index a8a7b7c8709b..3615592aa420 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 9d4c0fd881f3..4002fe1cafc8 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index aceb2af0774a..2bb0e8bb4150 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -416,10 +416,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 4597109b6725..a1585b57526f 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index af9d9162747b..bf22d701b5e4 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index ecc59fe68c20..a9ad3cde1aaf 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index 7fcf1ce9d1ce..1311e77bd226 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Animal.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Animal.java
index 7f01983b4318..f1ec67972a65 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Animal.java
@@ -127,10 +127,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ba491560f22f..895f299988a1 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index d6dcf8043a8b..e7ce23c89bbe 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ArrayTest.java
index 62370de480a6..513e4803a07e 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ArrayTest.java
@@ -158,10 +158,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/BigCat.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/BigCat.java
index d4b1411684ba..77dff7865947 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/BigCat.java
@@ -150,10 +150,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Capitalization.java
index 41a27fce3ffa..9d852cbdd084 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Capitalization.java
@@ -202,10 +202,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Cat.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Cat.java
index 3f3db574df2c..6e6ab302f94f 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Cat.java
@@ -113,10 +113,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Category.java
index af18144f0fe0..90617a6ae32c 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Category.java
@@ -113,10 +113,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ChildWithNullable.java
index 52f9ddb03ccd..1851fdfee2bb 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ChildWithNullable.java
@@ -108,10 +108,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ClassModel.java
index 25a586388b8d..fd544e5df23b 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ClassModel.java
@@ -78,10 +78,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Client.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Client.java
index 4a8c8790cdef..7aeec07e4f3a 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Client.java
@@ -77,10 +77,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ContainerDefaultValue.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ContainerDefaultValue.java
index e6ea6bc5cf1c..54bb741071ef 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ContainerDefaultValue.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ContainerDefaultValue.java
@@ -214,10 +214,7 @@ public class ContainerDefaultValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Dog.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Dog.java
index f6c867a3dc25..0c58588e64ab 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Dog.java
@@ -105,10 +105,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/EnumArrays.java
index 6056c1ec1a1c..51bc8303094b 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/EnumArrays.java
@@ -185,10 +185,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/EnumTest.java
index e9d55788aadd..212f34aff977 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/EnumTest.java
@@ -336,10 +336,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/File.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/File.java
index 82a6b3f27463..78c59285275a 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/File.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/File.java
@@ -78,10 +78,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index a8b779ea8438..5b4e1753fdbe 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -115,10 +115,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/FormatTest.java
index 59e61e9e830f..967fec0da07b 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/FormatTest.java
@@ -436,10 +436,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 6397fd3ecf8e..e63ae315a3e1 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/MapTest.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/MapTest.java
index 9f5a2fa62182..942e32302829 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/MapTest.java
@@ -226,10 +226,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index efe2e655cc91..3bd85bd2cb19 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -143,10 +143,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Model200Response.java
index e22bc05d5226..a72cfadef665 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Model200Response.java
@@ -105,10 +105,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ModelApiResponse.java
index 73f04a6c18c1..9c6b66e2f48d 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ModelList.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ModelList.java
index c51842058780..80fdc758baa0 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ModelList.java
@@ -79,10 +79,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ModelReturn.java
index a7566970d26c..dca7af0ce9a4 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ModelReturn.java
@@ -80,10 +80,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Name.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Name.java
index f20b913bbc5e..f44b3c0451c9 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Name.java
@@ -164,10 +164,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/NullableMapProperty.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/NullableMapProperty.java
index 9ee932742ca7..bcc5f2a798bc 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/NullableMapProperty.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/NullableMapProperty.java
@@ -101,10 +101,7 @@ public class NullableMapProperty {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/NumberOnly.java
index 25baacd0fd41..09215d0986d9 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/NumberOnly.java
@@ -78,10 +78,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Order.java
index 41e0199f9487..e91482f5fd5d 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/OuterComposite.java
index dbe72f1de977..6c2522771275 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/OuterComposite.java
@@ -128,10 +128,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ParentWithNullable.java
index f5413e1cfd15..a812b63cc916 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ParentWithNullable.java
@@ -161,10 +161,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Pet.java
index d0385e65b479..b7ce9bec70a6 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Pet.java
@@ -286,10 +286,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index cbbdd596a94b..fe30f5929587 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -102,10 +102,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
index cf4798f27b61..79bbf112b64c 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
@@ -152,10 +152,7 @@ public class ResponseObjectWithDifferentFieldNames {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/SpecialModelName.java
index 2fdee9f5cbd4..81c0eda3fd90 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -79,10 +79,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Tag.java
index 67902d5a856f..b5386348fb16 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 984e3b84da47..4bfb01e8abcd 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -205,10 +205,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/TypeHolderExample.java
index c91d9f02c756..24392490e464 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -231,10 +231,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/User.java
index 06eb7e7feca4..fe12d1abb8c3 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/XmlItem.java
index 4fd02655a44e..aa2acf368944 100644
--- a/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-builtin-validation/src/main/java/org/openapitools/model/XmlItem.java
@@ -862,10 +862,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index bc9d82f06cc7..e9dd14f56239 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index a8a7b7c8709b..3615592aa420 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 9d4c0fd881f3..4002fe1cafc8 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index aceb2af0774a..2bb0e8bb4150 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -416,10 +416,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 4597109b6725..a1585b57526f 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index af9d9162747b..bf22d701b5e4 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index ecc59fe68c20..a9ad3cde1aaf 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index 7fcf1ce9d1ce..1311e77bd226 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Animal.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Animal.java
index 7f01983b4318..f1ec67972a65 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Animal.java
@@ -127,10 +127,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ba491560f22f..895f299988a1 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index d6dcf8043a8b..e7ce23c89bbe 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayTest.java
index 62370de480a6..513e4803a07e 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayTest.java
@@ -158,10 +158,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/BigCat.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/BigCat.java
index d4b1411684ba..77dff7865947 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/BigCat.java
@@ -150,10 +150,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Capitalization.java
index 41a27fce3ffa..9d852cbdd084 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Capitalization.java
@@ -202,10 +202,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Cat.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Cat.java
index 3f3db574df2c..6e6ab302f94f 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Cat.java
@@ -113,10 +113,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Category.java
index af18144f0fe0..90617a6ae32c 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Category.java
@@ -113,10 +113,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ChildWithNullable.java
index 52f9ddb03ccd..1851fdfee2bb 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ChildWithNullable.java
@@ -108,10 +108,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ClassModel.java
index 25a586388b8d..fd544e5df23b 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ClassModel.java
@@ -78,10 +78,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Client.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Client.java
index 4a8c8790cdef..7aeec07e4f3a 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Client.java
@@ -77,10 +77,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ContainerDefaultValue.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ContainerDefaultValue.java
index e6ea6bc5cf1c..54bb741071ef 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ContainerDefaultValue.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ContainerDefaultValue.java
@@ -214,10 +214,7 @@ public class ContainerDefaultValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Dog.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Dog.java
index f6c867a3dc25..0c58588e64ab 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Dog.java
@@ -105,10 +105,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/EnumArrays.java
index 6056c1ec1a1c..51bc8303094b 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/EnumArrays.java
@@ -185,10 +185,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/EnumTest.java
index e9d55788aadd..212f34aff977 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/EnumTest.java
@@ -336,10 +336,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/File.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/File.java
index 82a6b3f27463..78c59285275a 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/File.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/File.java
@@ -78,10 +78,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index a8b779ea8438..5b4e1753fdbe 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -115,10 +115,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/FormatTest.java
index 59e61e9e830f..967fec0da07b 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/FormatTest.java
@@ -436,10 +436,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 6397fd3ecf8e..e63ae315a3e1 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/MapTest.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/MapTest.java
index 9f5a2fa62182..942e32302829 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/MapTest.java
@@ -226,10 +226,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index efe2e655cc91..3bd85bd2cb19 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -143,10 +143,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Model200Response.java
index e22bc05d5226..a72cfadef665 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Model200Response.java
@@ -105,10 +105,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ModelApiResponse.java
index 73f04a6c18c1..9c6b66e2f48d 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ModelList.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ModelList.java
index c51842058780..80fdc758baa0 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ModelList.java
@@ -79,10 +79,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ModelReturn.java
index a7566970d26c..dca7af0ce9a4 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ModelReturn.java
@@ -80,10 +80,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Name.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Name.java
index f20b913bbc5e..f44b3c0451c9 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Name.java
@@ -164,10 +164,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/NullableMapProperty.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/NullableMapProperty.java
index 9ee932742ca7..bcc5f2a798bc 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/NullableMapProperty.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/NullableMapProperty.java
@@ -101,10 +101,7 @@ public class NullableMapProperty {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/NumberOnly.java
index 25baacd0fd41..09215d0986d9 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/NumberOnly.java
@@ -78,10 +78,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Order.java
index 41e0199f9487..e91482f5fd5d 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/OuterComposite.java
index dbe72f1de977..6c2522771275 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/OuterComposite.java
@@ -128,10 +128,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ParentWithNullable.java
index f5413e1cfd15..a812b63cc916 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ParentWithNullable.java
@@ -161,10 +161,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Pet.java
index d0385e65b479..b7ce9bec70a6 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Pet.java
@@ -286,10 +286,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index cbbdd596a94b..fe30f5929587 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -102,10 +102,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
index cf4798f27b61..79bbf112b64c 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
@@ -152,10 +152,7 @@ public class ResponseObjectWithDifferentFieldNames {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/SpecialModelName.java
index 2fdee9f5cbd4..81c0eda3fd90 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -79,10 +79,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Tag.java
index 67902d5a856f..b5386348fb16 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 984e3b84da47..4bfb01e8abcd 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -205,10 +205,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/TypeHolderExample.java
index c91d9f02c756..24392490e464 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -231,10 +231,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/User.java
index 06eb7e7feca4..fe12d1abb8c3 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/XmlItem.java
index 4fd02655a44e..aa2acf368944 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/XmlItem.java
@@ -862,10 +862,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Category.java
index 1d01e6dcae87..04a37147726e 100644
--- a/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Category.java
@@ -103,10 +103,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/ModelApiResponse.java
index 95a3f47ca35a..1012a5a2bdb3 100644
--- a/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -130,10 +130,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Order.java
index 7b91efd30b55..fefd64b7bf9c 100644
--- a/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Order.java
@@ -244,10 +244,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Pet.java
index 35d21245ffdc..5c87f13202bf 100644
--- a/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Pet.java
@@ -283,10 +283,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Tag.java
index b79c22d00978..34510604ee4d 100644
--- a/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Tag.java
@@ -103,10 +103,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/User.java
index 5848bbdbc6fd..c93944d5ea2e 100644
--- a/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/User.java
@@ -253,10 +253,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index 90c8d53eea33..b87001aac7f3 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -132,10 +132,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index 2fb072cd6057..ae077abae3ef 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -133,10 +133,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index f3d857dd40e0..adc6aa622119 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -132,10 +132,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index d40c504da9d2..944678e51561 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -437,10 +437,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 168da9e999d2..2a387364efff 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -132,10 +132,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index 2fa38da0ec0b..6694549de7c3 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -133,10 +133,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index cc51e2fe2025..3eab47133d9c 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -133,10 +133,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index a673da9151b3..398ac3f11065 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -132,10 +132,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Animal.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Animal.java
index c08f67ae3562..0836af591d53 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Animal.java
@@ -135,10 +135,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 621c741411a4..b49f686174a4 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -101,10 +101,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 194abcb8cb9d..e9174032c546 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -101,10 +101,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayTest.java
index b99215ffb974..1b2c47a243d6 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayTest.java
@@ -171,10 +171,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/BigCat.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/BigCat.java
index b67f8ace073f..e92b5941eb58 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/BigCat.java
@@ -158,10 +158,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Capitalization.java
index a09d4678fa14..90c91c5b92e6 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Capitalization.java
@@ -218,10 +218,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Cat.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Cat.java
index a8afe9240339..1d4bb17172a5 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Cat.java
@@ -121,10 +121,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Category.java
index 80a868b4e1a7..422bf293c7a5 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Category.java
@@ -121,10 +121,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ChildWithNullable.java
index 90fa94c56911..972b616f0ae4 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ChildWithNullable.java
@@ -120,10 +120,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ClassModel.java
index 12d29472a55e..d8f2386fcc05 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ClassModel.java
@@ -89,10 +89,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Client.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Client.java
index 0cbfd2e5fa9b..3bb91573f9c7 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Client.java
@@ -88,10 +88,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ContainerDefaultValue.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ContainerDefaultValue.java
index 6f917479b4db..4a6f618e8fe7 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ContainerDefaultValue.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ContainerDefaultValue.java
@@ -224,10 +224,7 @@ public class ContainerDefaultValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Dog.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Dog.java
index b612adce7e4c..55cd4bcca4a2 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Dog.java
@@ -113,10 +113,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumArrays.java
index f665b6504f37..e4b60450bded 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumArrays.java
@@ -197,10 +197,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumTest.java
index fea965b6ba6a..b04bd080d94a 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumTest.java
@@ -347,10 +347,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/File.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/File.java
index 34631ba63a0f..12b61bb7d25f 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/File.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/File.java
@@ -89,10 +89,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index 12318c0ccba3..6840ba59e034 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -127,10 +127,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FormatTest.java
index 6aba6ecbe767..9cc38c91886e 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FormatTest.java
@@ -456,10 +456,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index c57cb6513740..9dd306cbb8ee 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -116,10 +116,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/MapTest.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/MapTest.java
index 18ec46e00e48..c91329d1cb33 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/MapTest.java
@@ -240,10 +240,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index b98ee1f2326a..889f210352e8 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -156,10 +156,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Model200Response.java
index 7f50c8060851..806347dd6fc4 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Model200Response.java
@@ -117,10 +117,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelApiResponse.java
index 7921b21314d2..bd3e52b07ec4 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -142,10 +142,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelList.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelList.java
index 70554b6c7486..df7cbc55a085 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelList.java
@@ -90,10 +90,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelReturn.java
index f403fdcc1e78..9240527b772b 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ModelReturn.java
@@ -91,10 +91,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Name.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Name.java
index cd67225d3f14..7377bb6e904d 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Name.java
@@ -174,10 +174,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/NullableMapProperty.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/NullableMapProperty.java
index a10c9502d24d..2991d532abb1 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/NullableMapProperty.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/NullableMapProperty.java
@@ -112,10 +112,7 @@ public class NullableMapProperty {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/NumberOnly.java
index 08e01d7fe663..ee4b35597d47 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/NumberOnly.java
@@ -89,10 +89,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Order.java
index 3467307f0625..8c15e7064821 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Order.java
@@ -259,10 +259,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/OuterComposite.java
index d56f0872f27d..4dd3c965c876 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/OuterComposite.java
@@ -141,10 +141,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ParentWithNullable.java
index 279324aaaaae..7fd13b969a79 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ParentWithNullable.java
@@ -173,10 +173,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Pet.java
index 5830dd7fb487..f024e800ce47 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Pet.java
@@ -298,10 +298,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index cc1f0b92fe8c..de245bc7635f 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -114,10 +114,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
index c3c36e1a0dff..d7c7e7218611 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
@@ -166,10 +166,7 @@ public class ResponseObjectWithDifferentFieldNames {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/SpecialModelName.java
index a2bc08b9f61d..609489ab7538 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -90,10 +90,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Tag.java
index d4ce246dd303..ccb0392b432e 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Tag.java
@@ -114,10 +114,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 75973da7b71a..b9ddddf1d832 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -205,10 +205,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/TypeHolderExample.java
index e08109b58dd0..1ae9051a12e3 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -231,10 +231,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/User.java
index 1bb5a6db283b..9f2f53f3ba61 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/User.java
@@ -270,10 +270,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/XmlItem.java
index 23ea12ebc68a..1eccb0e87844 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/XmlItem.java
@@ -901,10 +901,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Category.java
index b05ab761a644..9a7feeb55b19 100644
--- a/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Category.java
@@ -98,10 +98,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/ModelApiResponse.java
index 0dd252ceb3cf..aa00799ab36d 100644
--- a/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -124,10 +124,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Order.java
index 3a0302f27cfd..d4d12661ee2f 100644
--- a/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Order.java
@@ -235,10 +235,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Pet.java
index e1f842160c3b..45029db1b343 100644
--- a/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Pet.java
@@ -274,10 +274,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Tag.java
index 04c51972c07e..24bff58ed462 100644
--- a/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Tag.java
@@ -98,10 +98,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/User.java
index 29a76a29e3e0..ad99440de942 100644
--- a/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/User.java
@@ -242,10 +242,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index bc9d82f06cc7..e9dd14f56239 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index a8a7b7c8709b..3615592aa420 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 9d4c0fd881f3..4002fe1cafc8 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index aceb2af0774a..2bb0e8bb4150 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -416,10 +416,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 4597109b6725..a1585b57526f 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index af9d9162747b..bf22d701b5e4 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index ecc59fe68c20..a9ad3cde1aaf 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index 7fcf1ce9d1ce..1311e77bd226 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Animal.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Animal.java
index 7f01983b4318..f1ec67972a65 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Animal.java
@@ -127,10 +127,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ba491560f22f..895f299988a1 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index d6dcf8043a8b..e7ce23c89bbe 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayTest.java
index 62370de480a6..513e4803a07e 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayTest.java
@@ -158,10 +158,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/BigCat.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/BigCat.java
index d4b1411684ba..77dff7865947 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/BigCat.java
@@ -150,10 +150,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Capitalization.java
index 41a27fce3ffa..9d852cbdd084 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Capitalization.java
@@ -202,10 +202,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Cat.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Cat.java
index 3f3db574df2c..6e6ab302f94f 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Cat.java
@@ -113,10 +113,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Category.java
index af18144f0fe0..90617a6ae32c 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Category.java
@@ -113,10 +113,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ChildWithNullable.java
index 52f9ddb03ccd..1851fdfee2bb 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ChildWithNullable.java
@@ -108,10 +108,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ClassModel.java
index 25a586388b8d..fd544e5df23b 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ClassModel.java
@@ -78,10 +78,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Client.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Client.java
index 4a8c8790cdef..7aeec07e4f3a 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Client.java
@@ -77,10 +77,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ContainerDefaultValue.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ContainerDefaultValue.java
index e6ea6bc5cf1c..54bb741071ef 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ContainerDefaultValue.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ContainerDefaultValue.java
@@ -214,10 +214,7 @@ public class ContainerDefaultValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Dog.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Dog.java
index f6c867a3dc25..0c58588e64ab 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Dog.java
@@ -105,10 +105,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumArrays.java
index 6056c1ec1a1c..51bc8303094b 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumArrays.java
@@ -185,10 +185,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumTest.java
index e9d55788aadd..212f34aff977 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumTest.java
@@ -336,10 +336,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/File.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/File.java
index 82a6b3f27463..78c59285275a 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/File.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/File.java
@@ -78,10 +78,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index a8b779ea8438..5b4e1753fdbe 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -115,10 +115,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FormatTest.java
index 59e61e9e830f..967fec0da07b 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FormatTest.java
@@ -436,10 +436,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 6397fd3ecf8e..e63ae315a3e1 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/MapTest.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/MapTest.java
index 9f5a2fa62182..942e32302829 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/MapTest.java
@@ -226,10 +226,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index efe2e655cc91..3bd85bd2cb19 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -143,10 +143,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Model200Response.java
index e22bc05d5226..a72cfadef665 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Model200Response.java
@@ -105,10 +105,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelApiResponse.java
index 73f04a6c18c1..9c6b66e2f48d 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelList.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelList.java
index c51842058780..80fdc758baa0 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelList.java
@@ -79,10 +79,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelReturn.java
index a7566970d26c..dca7af0ce9a4 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ModelReturn.java
@@ -80,10 +80,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Name.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Name.java
index f20b913bbc5e..f44b3c0451c9 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Name.java
@@ -164,10 +164,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/NullableMapProperty.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/NullableMapProperty.java
index 9ee932742ca7..bcc5f2a798bc 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/NullableMapProperty.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/NullableMapProperty.java
@@ -101,10 +101,7 @@ public class NullableMapProperty {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/NumberOnly.java
index 25baacd0fd41..09215d0986d9 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/NumberOnly.java
@@ -78,10 +78,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Order.java
index 41e0199f9487..e91482f5fd5d 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/OuterComposite.java
index dbe72f1de977..6c2522771275 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/OuterComposite.java
@@ -128,10 +128,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ParentWithNullable.java
index f5413e1cfd15..a812b63cc916 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ParentWithNullable.java
@@ -161,10 +161,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Pet.java
index d0385e65b479..b7ce9bec70a6 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Pet.java
@@ -286,10 +286,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index cbbdd596a94b..fe30f5929587 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -102,10 +102,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
index cf4798f27b61..79bbf112b64c 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
@@ -152,10 +152,7 @@ public class ResponseObjectWithDifferentFieldNames {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/SpecialModelName.java
index 2fdee9f5cbd4..81c0eda3fd90 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -79,10 +79,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Tag.java
index 67902d5a856f..b5386348fb16 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 984e3b84da47..4bfb01e8abcd 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -205,10 +205,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/TypeHolderExample.java
index c91d9f02c756..24392490e464 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -231,10 +231,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/User.java
index 06eb7e7feca4..fe12d1abb8c3 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/XmlItem.java
index 4fd02655a44e..aa2acf368944 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/XmlItem.java
@@ -862,10 +862,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java
index cd8f14b3aa08..cf52b4aed0a0 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java
@@ -123,10 +123,7 @@ public class AdditionalPropertiesAnyTypeDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java
index 30985020cfbc..e4f9cdb1a71d 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java
@@ -124,10 +124,7 @@ public class AdditionalPropertiesArrayDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java
index e57f24f27c26..903de0df3da4 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java
@@ -123,10 +123,7 @@ public class AdditionalPropertiesBooleanDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
index a7386746f5fa..306d4eec0e10 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
@@ -418,10 +418,7 @@ public class AdditionalPropertiesClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java
index 1fa6bb7bdca9..df611cb49ab5 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java
@@ -123,10 +123,7 @@ public class AdditionalPropertiesIntegerDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java
index 255f0254f8de..b66b9c9eb0a3 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java
@@ -124,10 +124,7 @@ public class AdditionalPropertiesNumberDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java
index 0f4750b66a3a..d26b21fb6804 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java
@@ -124,10 +124,7 @@ public class AdditionalPropertiesObjectDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java
index d109821038b7..43f2eff5a64d 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java
@@ -123,10 +123,7 @@ public class AdditionalPropertiesStringDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AnimalDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AnimalDto.java
index ed07f4644a10..99e203af7716 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AnimalDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/AnimalDto.java
@@ -128,10 +128,7 @@ public class AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ApiResponseDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ApiResponseDto.java
index 4d545325049a..55edd6c7eb2e 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ApiResponseDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ApiResponseDto.java
@@ -129,10 +129,7 @@ public class ApiResponseDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
index 75d7d22cc095..6d8c6c32ffbe 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
@@ -92,10 +92,7 @@ public class ArrayOfArrayOfNumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
index 5e311a8deb9e..24c8477e2dc3 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
@@ -92,10 +92,7 @@ public class ArrayOfNumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ArrayTestDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ArrayTestDto.java
index 288e6ac6a5f4..9d02a230bbb9 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ArrayTestDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ArrayTestDto.java
@@ -160,10 +160,7 @@ public class ArrayTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/BigCatDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/BigCatDto.java
index 9caec2c7bc99..7f15ba3ba834 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/BigCatDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/BigCatDto.java
@@ -152,10 +152,7 @@ public class BigCatDto extends CatDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/CapitalizationDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/CapitalizationDto.java
index 0a9c9e984e71..76fa0b0102e7 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/CapitalizationDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/CapitalizationDto.java
@@ -204,10 +204,7 @@ public class CapitalizationDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/CatDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/CatDto.java
index af50132bcfe2..7a9284f34aaa 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/CatDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/CatDto.java
@@ -114,10 +114,7 @@ public class CatDto extends AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/CategoryDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/CategoryDto.java
index a38937d42e5a..4b2480586df3 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/CategoryDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/CategoryDto.java
@@ -115,10 +115,7 @@ public class CategoryDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ChildWithNullableDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ChildWithNullableDto.java
index db5e4e8846b1..3e1c85442952 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ChildWithNullableDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ChildWithNullableDto.java
@@ -110,10 +110,7 @@ public class ChildWithNullableDto extends ParentWithNullableDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ClassModelDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ClassModelDto.java
index 2f5a0f97b5bf..1405c5323189 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ClassModelDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ClassModelDto.java
@@ -80,10 +80,7 @@ public class ClassModelDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ClientDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ClientDto.java
index 1ec79ad12732..5f7a555300d6 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ClientDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ClientDto.java
@@ -79,10 +79,7 @@ public class ClientDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java
index 408f3fede302..192c0533e805 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java
@@ -216,10 +216,7 @@ public class ContainerDefaultValueDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/DogDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/DogDto.java
index 47e6087d111e..b7a132b395d6 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/DogDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/DogDto.java
@@ -107,10 +107,7 @@ public class DogDto extends AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/EnumArraysDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/EnumArraysDto.java
index cd99d0f9abf0..9b9538583b57 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/EnumArraysDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/EnumArraysDto.java
@@ -187,10 +187,7 @@ public class EnumArraysDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/EnumTestDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/EnumTestDto.java
index cd19a5f826de..ec99d5715c97 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/EnumTestDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/EnumTestDto.java
@@ -336,10 +336,7 @@ public class EnumTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/FileDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/FileDto.java
index c941bc6cbfb5..080630c06d61 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/FileDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/FileDto.java
@@ -80,10 +80,7 @@ public class FileDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
index cb0cb11084bd..d6eab2a8876c 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
@@ -117,10 +117,7 @@ public class FileSchemaTestClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/FormatTestDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/FormatTestDto.java
index 59c2f91cf801..f36bca743590 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/FormatTestDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/FormatTestDto.java
@@ -436,10 +436,7 @@ public class FormatTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
index 203c49135493..f269ad6a33ea 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ListDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ListDto.java
index df17a19a233b..b194fd5f1a20 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ListDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ListDto.java
@@ -79,10 +79,7 @@ public class ListDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/MapTestDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/MapTestDto.java
index 0db7b5d302d8..a4760272ba09 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/MapTestDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/MapTestDto.java
@@ -228,10 +228,7 @@ public class MapTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
index 5891a9f0b5d9..17b19984cebe 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
@@ -145,10 +145,7 @@ public class MixedPropertiesAndAdditionalPropertiesClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/Model200ResponseDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/Model200ResponseDto.java
index 78f1f146fd19..d33f33ac5b7c 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/Model200ResponseDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/Model200ResponseDto.java
@@ -105,10 +105,7 @@ public class Model200ResponseDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/NameDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/NameDto.java
index a4a3835cbc0d..a183a9564f05 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/NameDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/NameDto.java
@@ -166,10 +166,7 @@ public class NameDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/NullableMapPropertyDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/NullableMapPropertyDto.java
index e996ccc08739..6be04c42bc2d 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/NullableMapPropertyDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/NullableMapPropertyDto.java
@@ -103,10 +103,7 @@ public class NullableMapPropertyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/NumberOnlyDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/NumberOnlyDto.java
index 6c7def679565..e08766e110d9 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/NumberOnlyDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/NumberOnlyDto.java
@@ -80,10 +80,7 @@ public class NumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/OrderDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/OrderDto.java
index 4ad79364296f..cf6cd9e8aba1 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/OrderDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/OrderDto.java
@@ -245,10 +245,7 @@ public class OrderDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/OuterCompositeDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/OuterCompositeDto.java
index 15d9ff9b9a53..7473efd3ef7e 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/OuterCompositeDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/OuterCompositeDto.java
@@ -130,10 +130,7 @@ public class OuterCompositeDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ParentWithNullableDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ParentWithNullableDto.java
index e223d46460da..4128d2984145 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ParentWithNullableDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ParentWithNullableDto.java
@@ -162,10 +162,7 @@ public class ParentWithNullableDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/PetDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/PetDto.java
index 381f5058ee80..28a51738ca2d 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/PetDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/PetDto.java
@@ -288,10 +288,7 @@ public class PetDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
index c9d3267441dc..474eaf87c360 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
@@ -104,10 +104,7 @@ public class ReadOnlyFirstDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java
index cded8f6804fb..c9bb2b32de7f 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java
@@ -154,10 +154,7 @@ public class ResponseObjectWithDifferentFieldNamesDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ReturnDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ReturnDto.java
index d9a58aea0bfb..d97190139983 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ReturnDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/ReturnDto.java
@@ -80,10 +80,7 @@ public class ReturnDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/SpecialModelNameDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/SpecialModelNameDto.java
index 79b7ecfe4e1e..742e6fbb25ed 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/SpecialModelNameDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/SpecialModelNameDto.java
@@ -79,10 +79,7 @@ public class SpecialModelNameDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/TagDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/TagDto.java
index 22f33153a9e6..821043b3e6e9 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/TagDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/TagDto.java
@@ -104,10 +104,7 @@ public class TagDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java
index b45c32d85f04..df7cfb007dd3 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java
@@ -207,10 +207,7 @@ public class TypeHolderDefaultDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/TypeHolderExampleDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/TypeHolderExampleDto.java
index 789835ca551b..0cbea4f3b99b 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/TypeHolderExampleDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/TypeHolderExampleDto.java
@@ -233,10 +233,7 @@ public class TypeHolderExampleDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/UserDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/UserDto.java
index 44878f732015..689790d2b18a 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/UserDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/UserDto.java
@@ -254,10 +254,7 @@ public class UserDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/XmlItemDto.java b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/XmlItemDto.java
index 1b6a7fbadb97..8b9f4634ab67 100644
--- a/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/XmlItemDto.java
+++ b/samples/server/petstore/springboot-include-http-request-context/src/main/java/org/openapitools/model/XmlItemDto.java
@@ -864,10 +864,7 @@ public class XmlItemDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Category.java
index 357f641c5342..2644292a635e 100644
--- a/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Category.java
@@ -102,10 +102,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/ModelApiResponse.java
index b055d2a6c0c0..f841e45f0348 100644
--- a/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Order.java
index 0edad61a16d1..bfff46380e8d 100644
--- a/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Pet.java
index 4b2128266585..4561fa62380a 100644
--- a/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Pet.java
@@ -282,10 +282,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Tag.java
index 819f9a34d908..c9272229fa3c 100644
--- a/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/User.java
index b0d85aea44e6..96e8b8ecb311 100644
--- a/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index bc9d82f06cc7..e9dd14f56239 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index a8a7b7c8709b..3615592aa420 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 9d4c0fd881f3..4002fe1cafc8 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index aceb2af0774a..2bb0e8bb4150 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -416,10 +416,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 4597109b6725..a1585b57526f 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index af9d9162747b..bf22d701b5e4 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index ecc59fe68c20..a9ad3cde1aaf 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index 7fcf1ce9d1ce..1311e77bd226 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Animal.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Animal.java
index 7f01983b4318..f1ec67972a65 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Animal.java
@@ -127,10 +127,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ba491560f22f..895f299988a1 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index d6dcf8043a8b..e7ce23c89bbe 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayTest.java
index 62370de480a6..513e4803a07e 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayTest.java
@@ -158,10 +158,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/BigCat.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/BigCat.java
index d4b1411684ba..77dff7865947 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/BigCat.java
@@ -150,10 +150,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Capitalization.java
index 41a27fce3ffa..9d852cbdd084 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Capitalization.java
@@ -202,10 +202,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Cat.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Cat.java
index 3f3db574df2c..6e6ab302f94f 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Cat.java
@@ -113,10 +113,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Category.java
index af18144f0fe0..90617a6ae32c 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Category.java
@@ -113,10 +113,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ChildWithNullable.java
index 52f9ddb03ccd..1851fdfee2bb 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ChildWithNullable.java
@@ -108,10 +108,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ClassModel.java
index 25a586388b8d..fd544e5df23b 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ClassModel.java
@@ -78,10 +78,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Client.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Client.java
index 4a8c8790cdef..7aeec07e4f3a 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Client.java
@@ -77,10 +77,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ContainerDefaultValue.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ContainerDefaultValue.java
index e6ea6bc5cf1c..54bb741071ef 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ContainerDefaultValue.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ContainerDefaultValue.java
@@ -214,10 +214,7 @@ public class ContainerDefaultValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Dog.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Dog.java
index f6c867a3dc25..0c58588e64ab 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Dog.java
@@ -105,10 +105,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumArrays.java
index 6056c1ec1a1c..51bc8303094b 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumArrays.java
@@ -185,10 +185,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumTest.java
index e9d55788aadd..212f34aff977 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumTest.java
@@ -336,10 +336,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/File.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/File.java
index 82a6b3f27463..78c59285275a 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/File.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/File.java
@@ -78,10 +78,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index a8b779ea8438..5b4e1753fdbe 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -115,10 +115,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/FormatTest.java
index 59e61e9e830f..967fec0da07b 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/FormatTest.java
@@ -436,10 +436,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 6397fd3ecf8e..e63ae315a3e1 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/MapTest.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/MapTest.java
index 9f5a2fa62182..942e32302829 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/MapTest.java
@@ -226,10 +226,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index efe2e655cc91..3bd85bd2cb19 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -143,10 +143,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Model200Response.java
index e22bc05d5226..a72cfadef665 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Model200Response.java
@@ -105,10 +105,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelApiResponse.java
index 73f04a6c18c1..9c6b66e2f48d 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelList.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelList.java
index c51842058780..80fdc758baa0 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelList.java
@@ -79,10 +79,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelReturn.java
index a7566970d26c..dca7af0ce9a4 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ModelReturn.java
@@ -80,10 +80,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Name.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Name.java
index f20b913bbc5e..f44b3c0451c9 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Name.java
@@ -164,10 +164,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/NullableMapProperty.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/NullableMapProperty.java
index 9ee932742ca7..bcc5f2a798bc 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/NullableMapProperty.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/NullableMapProperty.java
@@ -101,10 +101,7 @@ public class NullableMapProperty {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/NumberOnly.java
index 25baacd0fd41..09215d0986d9 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/NumberOnly.java
@@ -78,10 +78,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Order.java
index 41e0199f9487..e91482f5fd5d 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/OuterComposite.java
index dbe72f1de977..6c2522771275 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/OuterComposite.java
@@ -128,10 +128,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ParentWithNullable.java
index f5413e1cfd15..a812b63cc916 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ParentWithNullable.java
@@ -161,10 +161,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Pet.java
index d0385e65b479..b7ce9bec70a6 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Pet.java
@@ -286,10 +286,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index cbbdd596a94b..fe30f5929587 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -102,10 +102,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
index cf4798f27b61..79bbf112b64c 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
@@ -152,10 +152,7 @@ public class ResponseObjectWithDifferentFieldNames {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/SpecialModelName.java
index 2fdee9f5cbd4..81c0eda3fd90 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -79,10 +79,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Tag.java
index 67902d5a856f..b5386348fb16 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 984e3b84da47..4bfb01e8abcd 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -205,10 +205,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderExample.java
index c91d9f02c756..24392490e464 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -231,10 +231,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/User.java
index 06eb7e7feca4..fe12d1abb8c3 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/XmlItem.java
index 4fd02655a44e..aa2acf368944 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/XmlItem.java
@@ -862,10 +862,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index bc9d82f06cc7..e9dd14f56239 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index a8a7b7c8709b..3615592aa420 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 9d4c0fd881f3..4002fe1cafc8 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index aceb2af0774a..2bb0e8bb4150 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -416,10 +416,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 4597109b6725..a1585b57526f 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index af9d9162747b..bf22d701b5e4 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index ecc59fe68c20..a9ad3cde1aaf 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index 7fcf1ce9d1ce..1311e77bd226 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Animal.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Animal.java
index 7f01983b4318..f1ec67972a65 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Animal.java
@@ -127,10 +127,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ba491560f22f..895f299988a1 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index d6dcf8043a8b..e7ce23c89bbe 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayTest.java
index 62370de480a6..513e4803a07e 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayTest.java
@@ -158,10 +158,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/BigCat.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/BigCat.java
index d4b1411684ba..77dff7865947 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/BigCat.java
@@ -150,10 +150,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Capitalization.java
index 41a27fce3ffa..9d852cbdd084 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Capitalization.java
@@ -202,10 +202,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Cat.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Cat.java
index 3f3db574df2c..6e6ab302f94f 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Cat.java
@@ -113,10 +113,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Category.java
index af18144f0fe0..90617a6ae32c 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Category.java
@@ -113,10 +113,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ChildWithNullable.java
index 52f9ddb03ccd..1851fdfee2bb 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ChildWithNullable.java
@@ -108,10 +108,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ClassModel.java
index 25a586388b8d..fd544e5df23b 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ClassModel.java
@@ -78,10 +78,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Client.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Client.java
index 4a8c8790cdef..7aeec07e4f3a 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Client.java
@@ -77,10 +77,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ContainerDefaultValue.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ContainerDefaultValue.java
index e6ea6bc5cf1c..54bb741071ef 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ContainerDefaultValue.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ContainerDefaultValue.java
@@ -214,10 +214,7 @@ public class ContainerDefaultValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Dog.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Dog.java
index f6c867a3dc25..0c58588e64ab 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Dog.java
@@ -105,10 +105,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/EnumArrays.java
index 6056c1ec1a1c..51bc8303094b 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/EnumArrays.java
@@ -185,10 +185,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/EnumTest.java
index e9d55788aadd..212f34aff977 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/EnumTest.java
@@ -336,10 +336,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/File.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/File.java
index 82a6b3f27463..78c59285275a 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/File.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/File.java
@@ -78,10 +78,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index a8b779ea8438..5b4e1753fdbe 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -115,10 +115,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/FormatTest.java
index 59e61e9e830f..967fec0da07b 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/FormatTest.java
@@ -436,10 +436,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 6397fd3ecf8e..e63ae315a3e1 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/MapTest.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/MapTest.java
index 9f5a2fa62182..942e32302829 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/MapTest.java
@@ -226,10 +226,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index efe2e655cc91..3bd85bd2cb19 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -143,10 +143,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Model200Response.java
index e22bc05d5226..a72cfadef665 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Model200Response.java
@@ -105,10 +105,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ModelApiResponse.java
index 73f04a6c18c1..9c6b66e2f48d 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ModelList.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ModelList.java
index c51842058780..80fdc758baa0 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ModelList.java
@@ -79,10 +79,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ModelReturn.java
index a7566970d26c..dca7af0ce9a4 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ModelReturn.java
@@ -80,10 +80,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Name.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Name.java
index f20b913bbc5e..f44b3c0451c9 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Name.java
@@ -164,10 +164,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/NullableMapProperty.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/NullableMapProperty.java
index 9ee932742ca7..bcc5f2a798bc 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/NullableMapProperty.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/NullableMapProperty.java
@@ -101,10 +101,7 @@ public class NullableMapProperty {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/NumberOnly.java
index 25baacd0fd41..09215d0986d9 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/NumberOnly.java
@@ -78,10 +78,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Order.java
index 41e0199f9487..e91482f5fd5d 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/OuterComposite.java
index dbe72f1de977..6c2522771275 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/OuterComposite.java
@@ -128,10 +128,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ParentWithNullable.java
index f5413e1cfd15..a812b63cc916 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ParentWithNullable.java
@@ -161,10 +161,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Pet.java
index d0385e65b479..b7ce9bec70a6 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Pet.java
@@ -286,10 +286,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index cbbdd596a94b..fe30f5929587 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -102,10 +102,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
index cf4798f27b61..79bbf112b64c 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
@@ -152,10 +152,7 @@ public class ResponseObjectWithDifferentFieldNames {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/SpecialModelName.java
index 2fdee9f5cbd4..81c0eda3fd90 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -79,10 +79,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Tag.java
index 67902d5a856f..b5386348fb16 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 984e3b84da47..4bfb01e8abcd 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -205,10 +205,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/TypeHolderExample.java
index c91d9f02c756..24392490e464 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -231,10 +231,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/User.java
index 06eb7e7feca4..fe12d1abb8c3 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/XmlItem.java
index 4fd02655a44e..aa2acf368944 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/XmlItem.java
@@ -862,10 +862,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index bc9d82f06cc7..e9dd14f56239 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index a8a7b7c8709b..3615592aa420 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 9d4c0fd881f3..4002fe1cafc8 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index e50c77be6775..27c0ef4e9e94 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -403,10 +403,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 4597109b6725..a1585b57526f 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index af9d9162747b..bf22d701b5e4 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index ecc59fe68c20..a9ad3cde1aaf 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index 7fcf1ce9d1ce..1311e77bd226 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Animal.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Animal.java
index 4479d246c94b..ab1e645bdd49 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Animal.java
@@ -126,10 +126,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ba491560f22f..895f299988a1 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index d6dcf8043a8b..e7ce23c89bbe 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayTest.java
index 62370de480a6..513e4803a07e 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayTest.java
@@ -158,10 +158,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Capitalization.java
index 41a27fce3ffa..9d852cbdd084 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Capitalization.java
@@ -202,10 +202,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Cat.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Cat.java
index 46c67abe6289..c972ed63268b 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Cat.java
@@ -105,10 +105,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Category.java
index af18144f0fe0..90617a6ae32c 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Category.java
@@ -113,10 +113,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ClassModel.java
index 25a586388b8d..fd544e5df23b 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ClassModel.java
@@ -78,10 +78,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Client.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Client.java
index 4a8c8790cdef..7aeec07e4f3a 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Client.java
@@ -77,10 +77,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Dog.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Dog.java
index f6c867a3dc25..0c58588e64ab 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Dog.java
@@ -105,10 +105,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/EnumArrays.java
index 6056c1ec1a1c..51bc8303094b 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/EnumArrays.java
@@ -185,10 +185,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/EnumTest.java
index e9d55788aadd..212f34aff977 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/EnumTest.java
@@ -336,10 +336,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/File.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/File.java
index 82a6b3f27463..78c59285275a 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/File.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/File.java
@@ -78,10 +78,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index a8b779ea8438..5b4e1753fdbe 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -115,10 +115,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/FormatTest.java
index 59e61e9e830f..967fec0da07b 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/FormatTest.java
@@ -436,10 +436,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 6397fd3ecf8e..e63ae315a3e1 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/MapTest.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/MapTest.java
index 9f5a2fa62182..942e32302829 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/MapTest.java
@@ -226,10 +226,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index efe2e655cc91..3bd85bd2cb19 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -143,10 +143,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Model200Response.java
index e22bc05d5226..a72cfadef665 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Model200Response.java
@@ -105,10 +105,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ModelApiResponse.java
index 73f04a6c18c1..9c6b66e2f48d 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ModelList.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ModelList.java
index c51842058780..80fdc758baa0 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ModelList.java
@@ -79,10 +79,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ModelReturn.java
index a7566970d26c..dca7af0ce9a4 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ModelReturn.java
@@ -80,10 +80,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Name.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Name.java
index f20b913bbc5e..f44b3c0451c9 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Name.java
@@ -164,10 +164,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/NumberOnly.java
index 25baacd0fd41..09215d0986d9 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/NumberOnly.java
@@ -78,10 +78,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Order.java
index 41e0199f9487..e91482f5fd5d 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/OuterComposite.java
index dbe72f1de977..6c2522771275 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/OuterComposite.java
@@ -128,10 +128,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Pet.java
index 4ee90b761275..329c1e3b1e8b 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Pet.java
@@ -275,10 +275,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index cbbdd596a94b..fe30f5929587 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -102,10 +102,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/SpecialModelName.java
index 5d263e9142ec..6539954e3815 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -79,10 +79,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Tag.java
index 67902d5a856f..b5386348fb16 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 01578e921e6f..7b76228526e8 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -205,10 +205,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/TypeHolderExample.java
index c91d9f02c756..24392490e464 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -231,10 +231,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/User.java
index 06eb7e7feca4..fe12d1abb8c3 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/XmlItem.java
index 4fd02655a44e..aa2acf368944 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/XmlItem.java
@@ -862,10 +862,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index bc9d82f06cc7..e9dd14f56239 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index a8a7b7c8709b..3615592aa420 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 9d4c0fd881f3..4002fe1cafc8 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index e50c77be6775..27c0ef4e9e94 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -403,10 +403,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 4597109b6725..a1585b57526f 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index af9d9162747b..bf22d701b5e4 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index ecc59fe68c20..a9ad3cde1aaf 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index 7fcf1ce9d1ce..1311e77bd226 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Animal.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Animal.java
index 4479d246c94b..ab1e645bdd49 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Animal.java
@@ -126,10 +126,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ba491560f22f..895f299988a1 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index d6dcf8043a8b..e7ce23c89bbe 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayTest.java
index 62370de480a6..513e4803a07e 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayTest.java
@@ -158,10 +158,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Capitalization.java
index 41a27fce3ffa..9d852cbdd084 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Capitalization.java
@@ -202,10 +202,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Cat.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Cat.java
index 46c67abe6289..c972ed63268b 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Cat.java
@@ -105,10 +105,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Category.java
index af18144f0fe0..90617a6ae32c 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Category.java
@@ -113,10 +113,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ClassModel.java
index 25a586388b8d..fd544e5df23b 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ClassModel.java
@@ -78,10 +78,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Client.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Client.java
index 4a8c8790cdef..7aeec07e4f3a 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Client.java
@@ -77,10 +77,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Dog.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Dog.java
index f6c867a3dc25..0c58588e64ab 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Dog.java
@@ -105,10 +105,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/EnumArrays.java
index 6056c1ec1a1c..51bc8303094b 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/EnumArrays.java
@@ -185,10 +185,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/EnumTest.java
index e9d55788aadd..212f34aff977 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/EnumTest.java
@@ -336,10 +336,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/File.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/File.java
index 82a6b3f27463..78c59285275a 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/File.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/File.java
@@ -78,10 +78,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index a8b779ea8438..5b4e1753fdbe 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -115,10 +115,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/FormatTest.java
index 59e61e9e830f..967fec0da07b 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/FormatTest.java
@@ -436,10 +436,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 6397fd3ecf8e..e63ae315a3e1 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/MapTest.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/MapTest.java
index 9f5a2fa62182..942e32302829 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/MapTest.java
@@ -226,10 +226,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index efe2e655cc91..3bd85bd2cb19 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -143,10 +143,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Model200Response.java
index e22bc05d5226..a72cfadef665 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Model200Response.java
@@ -105,10 +105,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ModelApiResponse.java
index 73f04a6c18c1..9c6b66e2f48d 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ModelList.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ModelList.java
index c51842058780..80fdc758baa0 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ModelList.java
@@ -79,10 +79,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ModelReturn.java
index a7566970d26c..dca7af0ce9a4 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ModelReturn.java
@@ -80,10 +80,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Name.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Name.java
index f20b913bbc5e..f44b3c0451c9 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Name.java
@@ -164,10 +164,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/NumberOnly.java
index 25baacd0fd41..09215d0986d9 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/NumberOnly.java
@@ -78,10 +78,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Order.java
index 41e0199f9487..e91482f5fd5d 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/OuterComposite.java
index dbe72f1de977..6c2522771275 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/OuterComposite.java
@@ -128,10 +128,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Pet.java
index 4ee90b761275..329c1e3b1e8b 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Pet.java
@@ -275,10 +275,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index cbbdd596a94b..fe30f5929587 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -102,10 +102,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/SpecialModelName.java
index 5d263e9142ec..6539954e3815 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -79,10 +79,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Tag.java
index 67902d5a856f..b5386348fb16 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 01578e921e6f..7b76228526e8 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -205,10 +205,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/TypeHolderExample.java
index c91d9f02c756..24392490e464 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -231,10 +231,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/User.java
index 06eb7e7feca4..fe12d1abb8c3 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/XmlItem.java
index 4fd02655a44e..aa2acf368944 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/XmlItem.java
@@ -862,10 +862,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index bc9d82f06cc7..e9dd14f56239 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index a8a7b7c8709b..3615592aa420 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 9d4c0fd881f3..4002fe1cafc8 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index e50c77be6775..27c0ef4e9e94 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -403,10 +403,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 4597109b6725..a1585b57526f 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index af9d9162747b..bf22d701b5e4 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index ecc59fe68c20..a9ad3cde1aaf 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index 7fcf1ce9d1ce..1311e77bd226 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Animal.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Animal.java
index 4479d246c94b..ab1e645bdd49 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Animal.java
@@ -126,10 +126,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ba491560f22f..895f299988a1 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index d6dcf8043a8b..e7ce23c89bbe 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayTest.java
index 62370de480a6..513e4803a07e 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayTest.java
@@ -158,10 +158,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Capitalization.java
index 41a27fce3ffa..9d852cbdd084 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Capitalization.java
@@ -202,10 +202,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Cat.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Cat.java
index 46c67abe6289..c972ed63268b 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Cat.java
@@ -105,10 +105,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Category.java
index af18144f0fe0..90617a6ae32c 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Category.java
@@ -113,10 +113,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ClassModel.java
index 25a586388b8d..fd544e5df23b 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ClassModel.java
@@ -78,10 +78,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Client.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Client.java
index 4a8c8790cdef..7aeec07e4f3a 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Client.java
@@ -77,10 +77,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Dog.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Dog.java
index f6c867a3dc25..0c58588e64ab 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Dog.java
@@ -105,10 +105,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/EnumArrays.java
index 6056c1ec1a1c..51bc8303094b 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/EnumArrays.java
@@ -185,10 +185,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/EnumTest.java
index e9d55788aadd..212f34aff977 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/EnumTest.java
@@ -336,10 +336,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/File.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/File.java
index 82a6b3f27463..78c59285275a 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/File.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/File.java
@@ -78,10 +78,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index a8b779ea8438..5b4e1753fdbe 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -115,10 +115,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/FormatTest.java
index 59e61e9e830f..967fec0da07b 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/FormatTest.java
@@ -436,10 +436,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 6397fd3ecf8e..e63ae315a3e1 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/MapTest.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/MapTest.java
index 9f5a2fa62182..942e32302829 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/MapTest.java
@@ -226,10 +226,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index efe2e655cc91..3bd85bd2cb19 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -143,10 +143,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Model200Response.java
index e22bc05d5226..a72cfadef665 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Model200Response.java
@@ -105,10 +105,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ModelApiResponse.java
index 73f04a6c18c1..9c6b66e2f48d 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ModelList.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ModelList.java
index c51842058780..80fdc758baa0 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ModelList.java
@@ -79,10 +79,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ModelReturn.java
index a7566970d26c..dca7af0ce9a4 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ModelReturn.java
@@ -80,10 +80,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Name.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Name.java
index f20b913bbc5e..f44b3c0451c9 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Name.java
@@ -164,10 +164,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/NumberOnly.java
index 25baacd0fd41..09215d0986d9 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/NumberOnly.java
@@ -78,10 +78,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Order.java
index 41e0199f9487..e91482f5fd5d 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/OuterComposite.java
index dbe72f1de977..6c2522771275 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/OuterComposite.java
@@ -128,10 +128,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Pet.java
index 4ee90b761275..329c1e3b1e8b 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Pet.java
@@ -275,10 +275,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index cbbdd596a94b..fe30f5929587 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -102,10 +102,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/SpecialModelName.java
index 5d263e9142ec..6539954e3815 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -79,10 +79,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Tag.java
index 67902d5a856f..b5386348fb16 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 01578e921e6f..7b76228526e8 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -205,10 +205,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/TypeHolderExample.java
index c91d9f02c756..24392490e464 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -231,10 +231,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/User.java
index 06eb7e7feca4..fe12d1abb8c3 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/XmlItem.java
index 4fd02655a44e..aa2acf368944 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/XmlItem.java
@@ -862,10 +862,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index bc9d82f06cc7..e9dd14f56239 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index a8a7b7c8709b..3615592aa420 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 9d4c0fd881f3..4002fe1cafc8 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index e50c77be6775..27c0ef4e9e94 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -403,10 +403,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 4597109b6725..a1585b57526f 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index af9d9162747b..bf22d701b5e4 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index ecc59fe68c20..a9ad3cde1aaf 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index 7fcf1ce9d1ce..1311e77bd226 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Animal.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Animal.java
index 4479d246c94b..ab1e645bdd49 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Animal.java
@@ -126,10 +126,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ba491560f22f..895f299988a1 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index d6dcf8043a8b..e7ce23c89bbe 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayTest.java
index 62370de480a6..513e4803a07e 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayTest.java
@@ -158,10 +158,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Capitalization.java
index 41a27fce3ffa..9d852cbdd084 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Capitalization.java
@@ -202,10 +202,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Cat.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Cat.java
index 46c67abe6289..c972ed63268b 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Cat.java
@@ -105,10 +105,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Category.java
index af18144f0fe0..90617a6ae32c 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Category.java
@@ -113,10 +113,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ClassModel.java
index 25a586388b8d..fd544e5df23b 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ClassModel.java
@@ -78,10 +78,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Client.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Client.java
index 4a8c8790cdef..7aeec07e4f3a 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Client.java
@@ -77,10 +77,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Dog.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Dog.java
index f6c867a3dc25..0c58588e64ab 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Dog.java
@@ -105,10 +105,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/EnumArrays.java
index 6056c1ec1a1c..51bc8303094b 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/EnumArrays.java
@@ -185,10 +185,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/EnumTest.java
index e9d55788aadd..212f34aff977 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/EnumTest.java
@@ -336,10 +336,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/File.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/File.java
index 82a6b3f27463..78c59285275a 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/File.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/File.java
@@ -78,10 +78,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index a8b779ea8438..5b4e1753fdbe 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -115,10 +115,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/FormatTest.java
index 59e61e9e830f..967fec0da07b 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/FormatTest.java
@@ -436,10 +436,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 6397fd3ecf8e..e63ae315a3e1 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/MapTest.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/MapTest.java
index 9f5a2fa62182..942e32302829 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/MapTest.java
@@ -226,10 +226,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index efe2e655cc91..3bd85bd2cb19 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -143,10 +143,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Model200Response.java
index e22bc05d5226..a72cfadef665 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Model200Response.java
@@ -105,10 +105,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ModelApiResponse.java
index 73f04a6c18c1..9c6b66e2f48d 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ModelList.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ModelList.java
index c51842058780..80fdc758baa0 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ModelList.java
@@ -79,10 +79,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ModelReturn.java
index a7566970d26c..dca7af0ce9a4 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ModelReturn.java
@@ -80,10 +80,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Name.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Name.java
index f20b913bbc5e..f44b3c0451c9 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Name.java
@@ -164,10 +164,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/NumberOnly.java
index 25baacd0fd41..09215d0986d9 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/NumberOnly.java
@@ -78,10 +78,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Order.java
index 41e0199f9487..e91482f5fd5d 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/OuterComposite.java
index dbe72f1de977..6c2522771275 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/OuterComposite.java
@@ -128,10 +128,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Pet.java
index 4ee90b761275..329c1e3b1e8b 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Pet.java
@@ -275,10 +275,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index cbbdd596a94b..fe30f5929587 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -102,10 +102,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/SpecialModelName.java
index 5d263e9142ec..6539954e3815 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -79,10 +79,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Tag.java
index 67902d5a856f..b5386348fb16 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 01578e921e6f..7b76228526e8 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -205,10 +205,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/TypeHolderExample.java
index c91d9f02c756..24392490e464 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -231,10 +231,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/User.java
index 06eb7e7feca4..fe12d1abb8c3 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/XmlItem.java
index 4fd02655a44e..aa2acf368944 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/XmlItem.java
@@ -862,10 +862,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Category.java
index a1d4d02fd36b..e06f3076fa1f 100644
--- a/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Category.java
@@ -101,10 +101,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/ModelApiResponse.java
index 435055a10a58..f4bc1158e557 100644
--- a/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -128,10 +128,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Order.java
index 7d244f08011b..beb88ead6f5a 100644
--- a/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Order.java
@@ -242,10 +242,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Pet.java
index 02c6109f0e6a..2845ae04fe0f 100644
--- a/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Pet.java
@@ -274,10 +274,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Tag.java
index 10e80a133066..ece3f449fa18 100644
--- a/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Tag.java
@@ -101,10 +101,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/User.java
index eabdbbb318cc..1e26e2d0fc35 100644
--- a/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/User.java
@@ -251,10 +251,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
index d77b4f267fbb..69c5f9fd575b 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
index cc57fea9897a..bff8651495c8 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
index 7cab78b03e3d..bac8947c0db3 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
index 7643804e4d0c..a57529f15fc0 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java
@@ -416,10 +416,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
index 2d281c7843bd..4c24477af6ba 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
index 8bf42dd6015c..06debd16f824 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
index c66c470554f4..0f864e63e522 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java
@@ -122,10 +122,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesString.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
index 01fcd1541d40..85c9c807a00e 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesString.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Animal.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Animal.java
index 2a24246d96ba..f5e99f0069e5 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Animal.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Animal.java
@@ -127,10 +127,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index d5503ad21e25..d7709f15bb22 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 5c91c0517185..89c4dba8e12c 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -90,10 +90,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayTest.java
index 7875357f559f..88965c7bc665 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayTest.java
@@ -158,10 +158,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/BigCat.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/BigCat.java
index 7eaed5fb33f4..0933c0187c1d 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/BigCat.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/BigCat.java
@@ -150,10 +150,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends Cat.Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Capitalization.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Capitalization.java
index a5540e7b293a..5fad4a24fb66 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Capitalization.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Capitalization.java
@@ -202,10 +202,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Cat.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Cat.java
index 3d85d7968061..74366371a08d 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Cat.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Cat.java
@@ -113,10 +113,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends Animal.Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Category.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Category.java
index c0c66eef7269..c1a096acfa5c 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Category.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Category.java
@@ -113,10 +113,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ChildWithNullable.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ChildWithNullable.java
index 72c12cca02ce..4f19baef6352 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ChildWithNullable.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ChildWithNullable.java
@@ -108,10 +108,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends ParentWithNullable.Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ClassModel.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ClassModel.java
index ae6410f8cceb..3954b445ebee 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ClassModel.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ClassModel.java
@@ -78,10 +78,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Client.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Client.java
index 73555b501b3d..c399568a0754 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Client.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Client.java
@@ -77,10 +77,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ContainerDefaultValue.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ContainerDefaultValue.java
index 44c18b974442..35de82f2f3ff 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ContainerDefaultValue.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ContainerDefaultValue.java
@@ -214,10 +214,7 @@ public class ContainerDefaultValue {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Dog.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Dog.java
index ed421eb00170..35d406e8d0b2 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Dog.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Dog.java
@@ -105,10 +105,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder extends Animal.Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/EnumArrays.java
index d6461b92e93b..8419f1de5aaf 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/EnumArrays.java
@@ -185,10 +185,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/EnumTest.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/EnumTest.java
index 0ce40de5cb57..abaedc83dc8f 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/EnumTest.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/EnumTest.java
@@ -336,10 +336,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/File.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/File.java
index c18f7e406133..68c2fd76dbf5 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/File.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/File.java
@@ -78,10 +78,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index 0de0e7d92103..a6c07fe1ca79 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -115,10 +115,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/FormatTest.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/FormatTest.java
index 5093d145ad26..0c9d9fc50798 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/FormatTest.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/FormatTest.java
@@ -436,10 +436,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/HasOnlyReadOnly.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
index 501bd2e3d457..7ddd21b6232a 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/HasOnlyReadOnly.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/MapTest.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/MapTest.java
index 8929cc6f5d1d..8a5e09eedb5d 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/MapTest.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/MapTest.java
@@ -226,10 +226,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 457ac110eb52..368684ed1399 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -143,10 +143,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Model200Response.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Model200Response.java
index 267ca00e0e6c..9e383c288421 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Model200Response.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Model200Response.java
@@ -105,10 +105,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ModelApiResponse.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ModelApiResponse.java
index c129b08b7e3a..9452aa539856 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ModelApiResponse.java
@@ -129,10 +129,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ModelList.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ModelList.java
index 42010ae9417c..2e04bb644304 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ModelList.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ModelList.java
@@ -79,10 +79,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ModelReturn.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ModelReturn.java
index 8fa8304f3568..2ec928492287 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ModelReturn.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ModelReturn.java
@@ -80,10 +80,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Name.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Name.java
index b1b4fb986e1e..787d65c6a9d6 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Name.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Name.java
@@ -164,10 +164,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/NullableMapProperty.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/NullableMapProperty.java
index 99c126508ef5..eb057fb3c7b0 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/NullableMapProperty.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/NullableMapProperty.java
@@ -101,10 +101,7 @@ public class NullableMapProperty {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/NumberOnly.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/NumberOnly.java
index fd60c718c89c..a7b5a622860a 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/NumberOnly.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/NumberOnly.java
@@ -78,10 +78,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Order.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Order.java
index 94e962ce9575..7e1a00394ef0 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Order.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Order.java
@@ -243,10 +243,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/OuterComposite.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/OuterComposite.java
index 831c89652c57..19ce8e9a9b72 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/OuterComposite.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/OuterComposite.java
@@ -128,10 +128,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ParentWithNullable.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ParentWithNullable.java
index 1fd57a2570eb..abcbaddba880 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ParentWithNullable.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ParentWithNullable.java
@@ -161,10 +161,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Pet.java
index 6d56d7ee10e2..8b9c6efb8833 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Pet.java
@@ -286,10 +286,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ReadOnlyFirst.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ReadOnlyFirst.java
index c2695dd71dad..2347eff45e7a 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ReadOnlyFirst.java
@@ -102,10 +102,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
index 1d9b7ccc3a37..b83b884483d6 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java
@@ -152,10 +152,7 @@ public class ResponseObjectWithDifferentFieldNames {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/SpecialModelName.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/SpecialModelName.java
index 58f02f0fd1cf..e1fafe867266 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/SpecialModelName.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/SpecialModelName.java
@@ -79,10 +79,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Tag.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Tag.java
index a72fce0a3f1a..28625fd8c0ca 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Tag.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Tag.java
@@ -102,10 +102,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/TypeHolderDefault.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/TypeHolderDefault.java
index 7e17e58fcb58..1b98e49622bc 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/TypeHolderDefault.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/TypeHolderDefault.java
@@ -205,10 +205,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/TypeHolderExample.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/TypeHolderExample.java
index cb5f44204f0e..e9bf2dfb584c 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/TypeHolderExample.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/TypeHolderExample.java
@@ -231,10 +231,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/User.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/User.java
index 31122263a981..d67d45f7565a 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/User.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/User.java
@@ -252,10 +252,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/XmlItem.java
index 505ee7a1a2ae..9b880e5187b6 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/XmlItem.java
@@ -862,10 +862,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
   
   public static class Builder {
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesAnyType.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesAnyType.java
index 74595b581168..100ff58b0ccc 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesAnyType.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesAnyType.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesAnyType {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesArray.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesArray.java
index 5319f46e9b83..753de53fd7a7 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesArray.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesArray.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesArray {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesBoolean.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesBoolean.java
index 6e2b50cbe7fd..0dd2ead1b258 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesBoolean.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesBoolean.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesBoolean {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesClass.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesClass.java
index 68543c549553..2b8f06279d71 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesClass.java
@@ -415,10 +415,7 @@ public class AdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesInteger.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesInteger.java
index 9c44aafe7a0b..b98e1d1cab83 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesInteger.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesInteger.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesInteger {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesNumber.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesNumber.java
index 18bf21e84f85..883f5274ac23 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesNumber.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesNumber.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesNumber {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesObject.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesObject.java
index 58d30b8ce2d9..e82b04aa11bb 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesObject.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesObject.java
@@ -121,10 +121,7 @@ public class AdditionalPropertiesObject {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesString.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesString.java
index 14fa61524697..66d869c39694 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesString.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/AdditionalPropertiesString.java
@@ -120,10 +120,7 @@ public class AdditionalPropertiesString {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Animal.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Animal.java
index 14a9f88b5edd..8fc6f3f011ae 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Animal.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Animal.java
@@ -126,10 +126,7 @@ public class Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayOfArrayOfNumberOnly.java
index 73865dc7a4fe..1b9ef81d0d0e 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayOfArrayOfNumberOnly.java
@@ -89,10 +89,7 @@ public class ArrayOfArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayOfNumberOnly.java
index 94affa366642..54a93c261a58 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayOfNumberOnly.java
@@ -89,10 +89,7 @@ public class ArrayOfNumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayTest.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayTest.java
index 56008eb07651..c4469792cbe7 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayTest.java
@@ -157,10 +157,7 @@ public class ArrayTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/BigCat.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/BigCat.java
index af8e17ccace4..f3a8c1b0fd3c 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/BigCat.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/BigCat.java
@@ -149,10 +149,7 @@ public class BigCat extends Cat {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Capitalization.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Capitalization.java
index bf733cf6dd00..8da384c7141a 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Capitalization.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Capitalization.java
@@ -201,10 +201,7 @@ public class Capitalization {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Cat.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Cat.java
index cf0e2b845e2f..a19d956dbab6 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Cat.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Cat.java
@@ -112,10 +112,7 @@ public class Cat extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Category.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Category.java
index 02c939ab5610..d33112d32463 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Category.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Category.java
@@ -112,10 +112,7 @@ public class Category {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ChildWithNullable.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ChildWithNullable.java
index e8a8b8186afa..8f2868570748 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ChildWithNullable.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ChildWithNullable.java
@@ -107,10 +107,7 @@ public class ChildWithNullable extends ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ClassModel.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ClassModel.java
index e22060eb7bdc..155d702fec8d 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ClassModel.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ClassModel.java
@@ -77,10 +77,7 @@ public class ClassModel {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Client.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Client.java
index c742f34d055c..086f4518aa2e 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Client.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Client.java
@@ -76,10 +76,7 @@ public class Client {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ContainerDefaultValue.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ContainerDefaultValue.java
index 746d16bb0fc0..6095189db99e 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ContainerDefaultValue.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ContainerDefaultValue.java
@@ -213,10 +213,7 @@ public class ContainerDefaultValue {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Dog.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Dog.java
index cfe4b76a4025..40be49fe697e 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Dog.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Dog.java
@@ -104,10 +104,7 @@ public class Dog extends Animal {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumArrays.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumArrays.java
index cf0424c1fbdc..552c72b61123 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumArrays.java
@@ -184,10 +184,7 @@ public class EnumArrays {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumTest.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumTest.java
index 3cf6629e5845..d5b1e588810a 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumTest.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumTest.java
@@ -335,10 +335,7 @@ public class EnumTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/File.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/File.java
index fbc3df2f2711..fe01a5fdfdef 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/File.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/File.java
@@ -77,10 +77,7 @@ public class File {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/FileSchemaTestClass.java
index 73dcacdb85d6..51d981f3f753 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/FileSchemaTestClass.java
@@ -114,10 +114,7 @@ public class FileSchemaTestClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/FormatTest.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/FormatTest.java
index 38dc854c9050..21fb6aaddbaa 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/FormatTest.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/FormatTest.java
@@ -435,10 +435,7 @@ public class FormatTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/HasOnlyReadOnly.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/HasOnlyReadOnly.java
index 24ebbf2dbe48..15d136c7936e 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/HasOnlyReadOnly.java
@@ -103,10 +103,7 @@ public class HasOnlyReadOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/MapTest.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/MapTest.java
index ed0de12dfa01..ba7508fb4aee 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/MapTest.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/MapTest.java
@@ -225,10 +225,7 @@ public class MapTest {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 38dd76a01f05..b248888a4d98 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -142,10 +142,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Model200Response.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Model200Response.java
index 740a77007d0d..85a180fa9de6 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Model200Response.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Model200Response.java
@@ -104,10 +104,7 @@ public class Model200Response {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelApiResponse.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelApiResponse.java
index 62193c583966..9dfcd68ad0d2 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelApiResponse.java
@@ -128,10 +128,7 @@ public class ModelApiResponse {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelList.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelList.java
index 2b87907cd7b6..2e558a9f497c 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelList.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelList.java
@@ -78,10 +78,7 @@ public class ModelList {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelReturn.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelReturn.java
index a2c76a721066..5908e9b64a98 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelReturn.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelReturn.java
@@ -79,10 +79,7 @@ public class ModelReturn {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Name.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Name.java
index 0847a7fc3009..2107e8fccbe8 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Name.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Name.java
@@ -163,10 +163,7 @@ public class Name {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/NullableMapProperty.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/NullableMapProperty.java
index a80bafc3d095..e94a6c7decda 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/NullableMapProperty.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/NullableMapProperty.java
@@ -100,10 +100,7 @@ public class NullableMapProperty {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/NumberOnly.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/NumberOnly.java
index 9e9fd9b9f479..2ba36216b08b 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/NumberOnly.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/NumberOnly.java
@@ -77,10 +77,7 @@ public class NumberOnly {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Order.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Order.java
index 88e39f826fe5..72773f528c2e 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Order.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Order.java
@@ -242,10 +242,7 @@ public class Order {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/OuterComposite.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/OuterComposite.java
index a96c928036ee..6b07a815dcd9 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/OuterComposite.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/OuterComposite.java
@@ -127,10 +127,7 @@ public class OuterComposite {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ParentWithNullable.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ParentWithNullable.java
index 4fcdf8868284..8b73b8e580ce 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ParentWithNullable.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ParentWithNullable.java
@@ -160,10 +160,7 @@ public class ParentWithNullable {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Pet.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Pet.java
index d5c653701e79..c327bf760e87 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Pet.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Pet.java
@@ -285,10 +285,7 @@ public class Pet {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ReadOnlyFirst.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ReadOnlyFirst.java
index 3de92d5ca057..a7b95a6beaaf 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ReadOnlyFirst.java
@@ -101,10 +101,7 @@ public class ReadOnlyFirst {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ResponseObjectWithDifferentFieldNames.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ResponseObjectWithDifferentFieldNames.java
index fb2e6d0e443e..580af9bbee30 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ResponseObjectWithDifferentFieldNames.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ResponseObjectWithDifferentFieldNames.java
@@ -151,10 +151,7 @@ public class ResponseObjectWithDifferentFieldNames {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/SpecialModelName.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/SpecialModelName.java
index f0dfbebc5e4a..d4f679d9d84d 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/SpecialModelName.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/SpecialModelName.java
@@ -78,10 +78,7 @@ public class SpecialModelName {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Tag.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Tag.java
index 6b39cdbd6eb7..06957a787009 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Tag.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Tag.java
@@ -101,10 +101,7 @@ public class Tag {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/TypeHolderDefault.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/TypeHolderDefault.java
index bb37b6ae37e6..9d6d9750700c 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/TypeHolderDefault.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/TypeHolderDefault.java
@@ -204,10 +204,7 @@ public class TypeHolderDefault {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/TypeHolderExample.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/TypeHolderExample.java
index 1b62d1631c36..bfb91bc15802 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/TypeHolderExample.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/TypeHolderExample.java
@@ -230,10 +230,7 @@ public class TypeHolderExample {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/User.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/User.java
index aabb81490a98..c0723c3d4d32 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/User.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/User.java
@@ -251,10 +251,7 @@ public class User {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/XmlItem.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/XmlItem.java
index 22b059102c1e..41349ff5d807 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/XmlItem.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/XmlItem.java
@@ -861,10 +861,7 @@ public class XmlItem {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
index 0c98a0508b48..230713df06f5 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
@@ -124,10 +124,7 @@ public class AdditionalPropertiesClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/AllOfWithSingleRefDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/AllOfWithSingleRefDto.java
index 581ac1d2f639..7768efea29f8 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/AllOfWithSingleRefDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/AllOfWithSingleRefDto.java
@@ -106,10 +106,7 @@ public class AllOfWithSingleRefDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/AnimalDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/AnimalDto.java
index dd80318cdd65..bbd7f8cd1cf4 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/AnimalDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/AnimalDto.java
@@ -127,10 +127,7 @@ public class AnimalDto implements com.custompackage.InterfaceToKeep, com.customp
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ApiResponseDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ApiResponseDto.java
index 4d545325049a..55edd6c7eb2e 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ApiResponseDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ApiResponseDto.java
@@ -129,10 +129,7 @@ public class ApiResponseDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
index 75d7d22cc095..6d8c6c32ffbe 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
@@ -92,10 +92,7 @@ public class ArrayOfArrayOfNumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
index 5e311a8deb9e..24c8477e2dc3 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
@@ -92,10 +92,7 @@ public class ArrayOfNumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ArrayTestDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ArrayTestDto.java
index 754b86547fdd..5a5737e977a3 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ArrayTestDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ArrayTestDto.java
@@ -160,10 +160,7 @@ public class ArrayTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/CapitalizationDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/CapitalizationDto.java
index 0a9c9e984e71..76fa0b0102e7 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/CapitalizationDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/CapitalizationDto.java
@@ -204,10 +204,7 @@ public class CapitalizationDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/CatDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/CatDto.java
index 118ffb1dee0a..507bad9c4148 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/CatDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/CatDto.java
@@ -106,10 +106,7 @@ public class CatDto extends AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/CategoryDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/CategoryDto.java
index a38937d42e5a..4b2480586df3 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/CategoryDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/CategoryDto.java
@@ -115,10 +115,7 @@ public class CategoryDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ChildWithNullableDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ChildWithNullableDto.java
index db5e4e8846b1..3e1c85442952 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ChildWithNullableDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ChildWithNullableDto.java
@@ -110,10 +110,7 @@ public class ChildWithNullableDto extends ParentWithNullableDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ClassModelDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ClassModelDto.java
index 2f5a0f97b5bf..1405c5323189 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ClassModelDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ClassModelDto.java
@@ -80,10 +80,7 @@ public class ClassModelDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ClientDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ClientDto.java
index 1ec79ad12732..5f7a555300d6 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ClientDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ClientDto.java
@@ -79,10 +79,7 @@ public class ClientDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/DeprecatedObjectDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/DeprecatedObjectDto.java
index d4a6d97082ee..57c450a7b383 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/DeprecatedObjectDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/DeprecatedObjectDto.java
@@ -81,10 +81,7 @@ public class DeprecatedObjectDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/DogDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/DogDto.java
index eabad5139ca9..538f8de5a685 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/DogDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/DogDto.java
@@ -106,10 +106,7 @@ public class DogDto extends AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/EnumArraysDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/EnumArraysDto.java
index cd99d0f9abf0..9b9538583b57 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/EnumArraysDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/EnumArraysDto.java
@@ -187,10 +187,7 @@ public class EnumArraysDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/EnumTestDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/EnumTestDto.java
index b0fb529314bd..2fa70b19cef1 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/EnumTestDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/EnumTestDto.java
@@ -427,10 +427,7 @@ public class EnumTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FakeBigDecimalMap200ResponseDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FakeBigDecimalMap200ResponseDto.java
index 42196114ca47..e0ccf52ed3a7 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FakeBigDecimalMap200ResponseDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FakeBigDecimalMap200ResponseDto.java
@@ -116,10 +116,7 @@ public class FakeBigDecimalMap200ResponseDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FileDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FileDto.java
index c941bc6cbfb5..080630c06d61 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FileDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FileDto.java
@@ -80,10 +80,7 @@ public class FileDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
index cb0cb11084bd..d6eab2a8876c 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
@@ -117,10 +117,7 @@ public class FileSchemaTestClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FooDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FooDto.java
index 39d406c826b5..c7d08a3a5ac1 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FooDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FooDto.java
@@ -79,10 +79,7 @@ public class FooDto implements com.custompackage.WithBar, com.custompackage.With
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FooGetDefaultResponseDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FooGetDefaultResponseDto.java
index cd258b7e25dd..db428131e31f 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FooGetDefaultResponseDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FooGetDefaultResponseDto.java
@@ -80,10 +80,7 @@ public class FooGetDefaultResponseDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FormatTestDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FormatTestDto.java
index 889dc6cc1acb..17941d955f5b 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FormatTestDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/FormatTestDto.java
@@ -486,10 +486,7 @@ public class FormatTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
index 203c49135493..f269ad6a33ea 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/HealthCheckResultDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/HealthCheckResultDto.java
index 00f6b2735007..2532865c145d 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/HealthCheckResultDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/HealthCheckResultDto.java
@@ -93,10 +93,7 @@ public class HealthCheckResultDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ListDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ListDto.java
index df17a19a233b..b194fd5f1a20 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ListDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ListDto.java
@@ -79,10 +79,7 @@ public class ListDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/MapTestDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/MapTestDto.java
index 0db7b5d302d8..a4760272ba09 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/MapTestDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/MapTestDto.java
@@ -228,10 +228,7 @@ public class MapTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
index 5891a9f0b5d9..17b19984cebe 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
@@ -145,10 +145,7 @@ public class MixedPropertiesAndAdditionalPropertiesClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/Model200ResponseDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/Model200ResponseDto.java
index 78f1f146fd19..d33f33ac5b7c 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/Model200ResponseDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/Model200ResponseDto.java
@@ -105,10 +105,7 @@ public class Model200ResponseDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/NameDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/NameDto.java
index a4a3835cbc0d..a183a9564f05 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/NameDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/NameDto.java
@@ -166,10 +166,7 @@ public class NameDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/NullableClassDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/NullableClassDto.java
index 2777b7b4d99e..718d6edbc728 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/NullableClassDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/NullableClassDto.java
@@ -466,10 +466,7 @@ public class NullableClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/NumberOnlyDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/NumberOnlyDto.java
index 6c7def679565..e08766e110d9 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/NumberOnlyDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/NumberOnlyDto.java
@@ -80,10 +80,7 @@ public class NumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ObjectWithDeprecatedFieldsDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ObjectWithDeprecatedFieldsDto.java
index 62a886f0be8d..1f4ff338b745 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ObjectWithDeprecatedFieldsDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ObjectWithDeprecatedFieldsDto.java
@@ -189,10 +189,7 @@ public class ObjectWithDeprecatedFieldsDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/OrderDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/OrderDto.java
index 4ad79364296f..cf6cd9e8aba1 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/OrderDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/OrderDto.java
@@ -245,10 +245,7 @@ public class OrderDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/OuterCompositeDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/OuterCompositeDto.java
index 15d9ff9b9a53..7473efd3ef7e 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/OuterCompositeDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/OuterCompositeDto.java
@@ -130,10 +130,7 @@ public class OuterCompositeDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/OuterObjectWithEnumPropertyDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/OuterObjectWithEnumPropertyDto.java
index 7788b31a38f1..df01335eaf57 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/OuterObjectWithEnumPropertyDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/OuterObjectWithEnumPropertyDto.java
@@ -92,10 +92,7 @@ public class OuterObjectWithEnumPropertyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ParentWithNullableDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ParentWithNullableDto.java
index e223d46460da..4128d2984145 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ParentWithNullableDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ParentWithNullableDto.java
@@ -162,10 +162,7 @@ public class ParentWithNullableDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/PetDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/PetDto.java
index 44c70385dc61..89bbd11e2d78 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/PetDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/PetDto.java
@@ -281,10 +281,7 @@ public class PetDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
index c9d3267441dc..474eaf87c360 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
@@ -104,10 +104,7 @@ public class ReadOnlyFirstDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ReturnDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ReturnDto.java
index d9a58aea0bfb..d97190139983 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ReturnDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/ReturnDto.java
@@ -80,10 +80,7 @@ public class ReturnDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/SpecialModelNameDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/SpecialModelNameDto.java
index 79b7ecfe4e1e..742e6fbb25ed 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/SpecialModelNameDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/SpecialModelNameDto.java
@@ -79,10 +79,7 @@ public class SpecialModelNameDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/TagDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/TagDto.java
index 22f33153a9e6..821043b3e6e9 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/TagDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/TagDto.java
@@ -104,10 +104,7 @@ public class TagDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequestDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequestDto.java
index 85351a6658be..3befe5fd6786 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequestDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/TestInlineFreeformAdditionalPropertiesRequestDto.java
@@ -123,10 +123,7 @@ public class TestInlineFreeformAdditionalPropertiesRequestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/UserDto.java b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/UserDto.java
index 44878f732015..689790d2b18a 100644
--- a/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/UserDto.java
+++ b/samples/server/petstore/springboot-x-implements-skip/src/main/java/org/openapitools/model/UserDto.java
@@ -254,10 +254,7 @@ public class UserDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java
index cd8f14b3aa08..cf52b4aed0a0 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesAnyTypeDto.java
@@ -123,10 +123,7 @@ public class AdditionalPropertiesAnyTypeDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java
index 30985020cfbc..e4f9cdb1a71d 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesArrayDto.java
@@ -124,10 +124,7 @@ public class AdditionalPropertiesArrayDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java
index e57f24f27c26..903de0df3da4 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesBooleanDto.java
@@ -123,10 +123,7 @@ public class AdditionalPropertiesBooleanDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
index a7386746f5fa..306d4eec0e10 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesClassDto.java
@@ -418,10 +418,7 @@ public class AdditionalPropertiesClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java
index 1fa6bb7bdca9..df611cb49ab5 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesIntegerDto.java
@@ -123,10 +123,7 @@ public class AdditionalPropertiesIntegerDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java
index 255f0254f8de..b66b9c9eb0a3 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesNumberDto.java
@@ -124,10 +124,7 @@ public class AdditionalPropertiesNumberDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java
index 0f4750b66a3a..d26b21fb6804 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesObjectDto.java
@@ -124,10 +124,7 @@ public class AdditionalPropertiesObjectDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java
index d109821038b7..43f2eff5a64d 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AdditionalPropertiesStringDto.java
@@ -123,10 +123,7 @@ public class AdditionalPropertiesStringDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AnimalDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AnimalDto.java
index ed07f4644a10..99e203af7716 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AnimalDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/AnimalDto.java
@@ -128,10 +128,7 @@ public class AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ApiResponseDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ApiResponseDto.java
index 4d545325049a..55edd6c7eb2e 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ApiResponseDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ApiResponseDto.java
@@ -129,10 +129,7 @@ public class ApiResponseDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
index 75d7d22cc095..6d8c6c32ffbe 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
@@ -92,10 +92,7 @@ public class ArrayOfArrayOfNumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
index 5e311a8deb9e..24c8477e2dc3 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
@@ -92,10 +92,7 @@ public class ArrayOfNumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayTestDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayTestDto.java
index 288e6ac6a5f4..9d02a230bbb9 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayTestDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayTestDto.java
@@ -160,10 +160,7 @@ public class ArrayTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/BigCatDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/BigCatDto.java
index 9caec2c7bc99..7f15ba3ba834 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/BigCatDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/BigCatDto.java
@@ -152,10 +152,7 @@ public class BigCatDto extends CatDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/CapitalizationDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/CapitalizationDto.java
index 0a9c9e984e71..76fa0b0102e7 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/CapitalizationDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/CapitalizationDto.java
@@ -204,10 +204,7 @@ public class CapitalizationDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/CatDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/CatDto.java
index af50132bcfe2..7a9284f34aaa 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/CatDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/CatDto.java
@@ -114,10 +114,7 @@ public class CatDto extends AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/CategoryDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/CategoryDto.java
index a38937d42e5a..4b2480586df3 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/CategoryDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/CategoryDto.java
@@ -115,10 +115,7 @@ public class CategoryDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ChildWithNullableDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ChildWithNullableDto.java
index db5e4e8846b1..3e1c85442952 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ChildWithNullableDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ChildWithNullableDto.java
@@ -110,10 +110,7 @@ public class ChildWithNullableDto extends ParentWithNullableDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ClassModelDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ClassModelDto.java
index 2f5a0f97b5bf..1405c5323189 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ClassModelDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ClassModelDto.java
@@ -80,10 +80,7 @@ public class ClassModelDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ClientDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ClientDto.java
index 1ec79ad12732..5f7a555300d6 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ClientDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ClientDto.java
@@ -79,10 +79,7 @@ public class ClientDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java
index 408f3fede302..192c0533e805 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ContainerDefaultValueDto.java
@@ -216,10 +216,7 @@ public class ContainerDefaultValueDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/DogDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/DogDto.java
index 47e6087d111e..b7a132b395d6 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/DogDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/DogDto.java
@@ -107,10 +107,7 @@ public class DogDto extends AnimalDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/EnumArraysDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/EnumArraysDto.java
index cd99d0f9abf0..9b9538583b57 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/EnumArraysDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/EnumArraysDto.java
@@ -187,10 +187,7 @@ public class EnumArraysDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/EnumTestDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/EnumTestDto.java
index cd19a5f826de..ec99d5715c97 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/EnumTestDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/EnumTestDto.java
@@ -336,10 +336,7 @@ public class EnumTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/FileDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/FileDto.java
index c941bc6cbfb5..080630c06d61 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/FileDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/FileDto.java
@@ -80,10 +80,7 @@ public class FileDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
index cb0cb11084bd..d6eab2a8876c 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
@@ -117,10 +117,7 @@ public class FileSchemaTestClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/FormatTestDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/FormatTestDto.java
index 59c2f91cf801..f36bca743590 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/FormatTestDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/FormatTestDto.java
@@ -436,10 +436,7 @@ public class FormatTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
index 203c49135493..f269ad6a33ea 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/HasOnlyReadOnlyDto.java
@@ -104,10 +104,7 @@ public class HasOnlyReadOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ListDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ListDto.java
index df17a19a233b..b194fd5f1a20 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ListDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ListDto.java
@@ -79,10 +79,7 @@ public class ListDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/MapTestDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/MapTestDto.java
index 0db7b5d302d8..a4760272ba09 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/MapTestDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/MapTestDto.java
@@ -228,10 +228,7 @@ public class MapTestDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
index 5891a9f0b5d9..17b19984cebe 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClassDto.java
@@ -145,10 +145,7 @@ public class MixedPropertiesAndAdditionalPropertiesClassDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/Model200ResponseDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/Model200ResponseDto.java
index 78f1f146fd19..d33f33ac5b7c 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/Model200ResponseDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/Model200ResponseDto.java
@@ -105,10 +105,7 @@ public class Model200ResponseDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/NameDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/NameDto.java
index a4a3835cbc0d..a183a9564f05 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/NameDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/NameDto.java
@@ -166,10 +166,7 @@ public class NameDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/NullableMapPropertyDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/NullableMapPropertyDto.java
index e996ccc08739..6be04c42bc2d 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/NullableMapPropertyDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/NullableMapPropertyDto.java
@@ -103,10 +103,7 @@ public class NullableMapPropertyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/NumberOnlyDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/NumberOnlyDto.java
index 6c7def679565..e08766e110d9 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/NumberOnlyDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/NumberOnlyDto.java
@@ -80,10 +80,7 @@ public class NumberOnlyDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/OrderDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/OrderDto.java
index 4ad79364296f..cf6cd9e8aba1 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/OrderDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/OrderDto.java
@@ -245,10 +245,7 @@ public class OrderDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/OuterCompositeDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/OuterCompositeDto.java
index 15d9ff9b9a53..7473efd3ef7e 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/OuterCompositeDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/OuterCompositeDto.java
@@ -130,10 +130,7 @@ public class OuterCompositeDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ParentWithNullableDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ParentWithNullableDto.java
index e223d46460da..4128d2984145 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ParentWithNullableDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ParentWithNullableDto.java
@@ -162,10 +162,7 @@ public class ParentWithNullableDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/PetDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/PetDto.java
index 381f5058ee80..28a51738ca2d 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/PetDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/PetDto.java
@@ -288,10 +288,7 @@ public class PetDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
index c9d3267441dc..474eaf87c360 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ReadOnlyFirstDto.java
@@ -104,10 +104,7 @@ public class ReadOnlyFirstDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java
index cded8f6804fb..c9bb2b32de7f 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNamesDto.java
@@ -154,10 +154,7 @@ public class ResponseObjectWithDifferentFieldNamesDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ReturnDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ReturnDto.java
index d9a58aea0bfb..d97190139983 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ReturnDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ReturnDto.java
@@ -80,10 +80,7 @@ public class ReturnDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/SpecialModelNameDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/SpecialModelNameDto.java
index 79b7ecfe4e1e..742e6fbb25ed 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/SpecialModelNameDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/SpecialModelNameDto.java
@@ -79,10 +79,7 @@ public class SpecialModelNameDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/TagDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/TagDto.java
index 22f33153a9e6..821043b3e6e9 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/TagDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/TagDto.java
@@ -104,10 +104,7 @@ public class TagDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java
index b45c32d85f04..df7cfb007dd3 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/TypeHolderDefaultDto.java
@@ -207,10 +207,7 @@ public class TypeHolderDefaultDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/TypeHolderExampleDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/TypeHolderExampleDto.java
index 789835ca551b..0cbea4f3b99b 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/TypeHolderExampleDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/TypeHolderExampleDto.java
@@ -233,10 +233,7 @@ public class TypeHolderExampleDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/UserDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/UserDto.java
index 44878f732015..689790d2b18a 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/UserDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/UserDto.java
@@ -254,10 +254,7 @@ public class UserDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }
 
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/XmlItemDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/XmlItemDto.java
index 1b6a7fbadb97..8b9f4634ab67 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/XmlItemDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/XmlItemDto.java
@@ -864,10 +864,7 @@ public class XmlItemDto {
    * (except the first line).
    */
   private String toIndentedString(@Nullable Object o) {
-    if (o == null) {
-      return "null";
-    }
-    return o.toString().replace("\n", "\n    ");
+    return o == null ? "null" : o.toString().replace("\n", "\n    ");
   }
 }