diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java
index 0f6872b162e..0d2a6c047f9 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java
@@ -49,6 +49,7 @@ public class CppRestSdkClientCodegen extends AbstractCppCodegen {
 
     public static final String DECLSPEC = "declspec";
     public static final String DEFAULT_INCLUDE = "defaultInclude";
+    public static final String GENERATE_GMOCKS_FOR_APIS = "generateGMocksForApis";
 
     protected String packageVersion = "1.0.0";
     protected String declspec = "";
@@ -114,6 +115,9 @@ public class CppRestSdkClientCodegen extends AbstractCppCodegen {
         addOption(DEFAULT_INCLUDE,
                 "The default include statement that should be placed in all headers for including things like the declspec (convention: #include \"Commons.h\" ",
                 this.defaultInclude);
+        addOption(GENERATE_GMOCKS_FOR_APIS,
+                "Generate Google Mock classes for APIs.",
+                null);
 
         supportingFiles.add(new SupportingFile("modelbase-header.mustache", "", "ModelBase.h"));
         supportingFiles.add(new SupportingFile("modelbase-source.mustache", "", "ModelBase.cpp"));
@@ -177,6 +181,11 @@ public class CppRestSdkClientCodegen extends AbstractCppCodegen {
             defaultInclude = additionalProperties.get(DEFAULT_INCLUDE).toString();
         }
 
+        if (convertPropertyToBoolean(GENERATE_GMOCKS_FOR_APIS)) {
+            apiTemplateFiles.put("api-gmock.mustache", "GMock.h");
+            additionalProperties.put("gmockApis", "true");
+        }
+
         additionalProperties.put("modelNamespaceDeclarations", modelPackage.split("\\."));
         additionalProperties.put("modelNamespace", modelPackage.replaceAll("\\.", "::"));
         additionalProperties.put("modelHeaderGuardPrefix", modelPackage.replaceAll("\\.", "_").toUpperCase());
diff --git a/modules/openapi-generator/src/main/resources/cpp-rest-sdk-client/api-gmock.mustache b/modules/openapi-generator/src/main/resources/cpp-rest-sdk-client/api-gmock.mustache
new file mode 100644
index 00000000000..804099e4caf
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/cpp-rest-sdk-client/api-gmock.mustache
@@ -0,0 +1,41 @@
+{{>licenseInfo}}
+{{#operations}}
+#ifndef {{apiHeaderGuardPrefix}}_{{classname}}GMock_H_
+#define {{apiHeaderGuardPrefix}}_{{classname}}GMock_H_
+
+#include <gmock/gmock.h>
+
+#include "{{classname}}.h"
+
+{{#apiNamespaceDeclarations}}
+namespace {{this}} {
+{{/apiNamespaceDeclarations}}
+
+using namespace {{modelNamespace}};
+
+
+class {{declspec}} {{classname}}Mock : public I{{classname}}
+{
+public:
+    using Base = I{{classname}};
+
+    {{classname}}Mock() = default;
+    explicit {{classname}}Mock( std::shared_ptr<ApiClient> apiClient ) { };
+    ~{{classname}}Mock() override = default;
+
+    {{#operation}}
+    MOCK_METHOD{{allParams.size}}( {{operationId}}, pplx::task<{{#returnType}}{{{returnType}}}{{/returnType}}{{^returnType}}void{{/returnType}}> (
+        {{#allParams}}
+        {{^required}}boost::optional<{{/required}}{{#isFile}}std::shared_ptr<{{/isFile}}{{{dataType}}}{{#isFile}}>{{/isFile}}{{^required}}>{{/required}} {{paramName}}{{#hasMore}},{{/hasMore}}
+        {{/allParams}}
+    ) );
+    {{/operation}}
+};
+
+{{#apiNamespaceDeclarations}}
+}
+{{/apiNamespaceDeclarations}}
+
+#endif /* {{apiHeaderGuardPrefix}}_{{classname}}GMock_H_ */
+
+{{/operations}}
diff --git a/modules/openapi-generator/src/main/resources/cpp-rest-sdk-client/api-header.mustache b/modules/openapi-generator/src/main/resources/cpp-rest-sdk-client/api-header.mustache
index 49200e4f2ab..ec97511314f 100644
--- a/modules/openapi-generator/src/main/resources/cpp-rest-sdk-client/api-header.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-rest-sdk-client/api-header.mustache
@@ -22,11 +22,38 @@ namespace {{this}} {
 
 using namespace {{modelNamespace}};
 
-class {{declspec}} {{classname}}
+{{#gmockApis}}
+class {{declspec}} I{{classname}}
 {
 public:
-    {{classname}}( std::shared_ptr<ApiClient> apiClient );
-    virtual ~{{classname}}();
+    I{{classname}}() = default;
+    virtual ~I{{classname}}() = default;
+
+    {{#operation}}
+    virtual pplx::task<{{#returnType}}{{{returnType}}}{{/returnType}}{{^returnType}}void{{/returnType}}> {{operationId}}(
+        {{#allParams}}
+        {{^required}}boost::optional<{{/required}}{{#isFile}}std::shared_ptr<{{/isFile}}{{{dataType}}}{{#isFile}}>{{/isFile}}{{^required}}>{{/required}} {{paramName}}{{#hasMore}},{{/hasMore}}
+        {{/allParams}}
+    ) = 0;
+    {{/operation}}
+};{{/gmockApis}}
+
+class {{declspec}} {{classname}} {{#gmockApis}} : public I{{classname}} {{/gmockApis}}
+{
+public:
+    {{#gmockApis}}
+    using Base = I{{classname}};
+    {{/gmockApis}}
+
+    explicit {{classname}}( std::shared_ptr<ApiClient> apiClient );
+
+    {{#gmockApis}}
+    ~{{classname}}() override;
+    {{/gmockApis}}
+    {{^gmockApis}}
+    virtual ~{{classname}}() = default;
+    {{/gmockApis}}
+
     {{#operation}}
     /// <summary>
     /// {{summary}}
@@ -41,7 +68,7 @@ public:
         {{#allParams}}
         {{^required}}boost::optional<{{/required}}{{#isFile}}std::shared_ptr<{{/isFile}}{{{dataType}}}{{#isFile}}>{{/isFile}}{{^required}}>{{/required}} {{paramName}}{{#hasMore}},{{/hasMore}}
         {{/allParams}}
-    );
+    ){{#gmockApis}} override{{/gmockApis}};
     {{/operation}}
 
 protected:
diff --git a/samples/client/petstore/cpp-restsdk/.openapi-generator/VERSION b/samples/client/petstore/cpp-restsdk/.openapi-generator/VERSION
index 096bf47efe3..dde25ef08e8 100644
--- a/samples/client/petstore/cpp-restsdk/.openapi-generator/VERSION
+++ b/samples/client/petstore/cpp-restsdk/.openapi-generator/VERSION
@@ -1 +1 @@
-3.0.0-SNAPSHOT
\ No newline at end of file
+3.1.1-SNAPSHOT
\ No newline at end of file
diff --git a/samples/client/petstore/cpp-restsdk/ApiClient.cpp b/samples/client/petstore/cpp-restsdk/ApiClient.cpp
index 448f377926e..1b2256bcdbd 100644
--- a/samples/client/petstore/cpp-restsdk/ApiClient.cpp
+++ b/samples/client/petstore/cpp-restsdk/ApiClient.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/ApiClient.h b/samples/client/petstore/cpp-restsdk/ApiClient.h
index 355a119f395..ace5dbc15b5 100644
--- a/samples/client/petstore/cpp-restsdk/ApiClient.h
+++ b/samples/client/petstore/cpp-restsdk/ApiClient.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/ApiConfiguration.cpp b/samples/client/petstore/cpp-restsdk/ApiConfiguration.cpp
index 2d5d39513ec..eba08373998 100644
--- a/samples/client/petstore/cpp-restsdk/ApiConfiguration.cpp
+++ b/samples/client/petstore/cpp-restsdk/ApiConfiguration.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/ApiConfiguration.h b/samples/client/petstore/cpp-restsdk/ApiConfiguration.h
index c39b29fc61f..8f39ba36aa9 100644
--- a/samples/client/petstore/cpp-restsdk/ApiConfiguration.h
+++ b/samples/client/petstore/cpp-restsdk/ApiConfiguration.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/ApiException.cpp b/samples/client/petstore/cpp-restsdk/ApiException.cpp
index bb41df86f97..c6d9e2ea004 100644
--- a/samples/client/petstore/cpp-restsdk/ApiException.cpp
+++ b/samples/client/petstore/cpp-restsdk/ApiException.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/ApiException.h b/samples/client/petstore/cpp-restsdk/ApiException.h
index 6073db8d1ec..da0cb95a516 100644
--- a/samples/client/petstore/cpp-restsdk/ApiException.h
+++ b/samples/client/petstore/cpp-restsdk/ApiException.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/HttpContent.cpp b/samples/client/petstore/cpp-restsdk/HttpContent.cpp
index 8922e724304..cc09bfac319 100644
--- a/samples/client/petstore/cpp-restsdk/HttpContent.cpp
+++ b/samples/client/petstore/cpp-restsdk/HttpContent.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/HttpContent.h b/samples/client/petstore/cpp-restsdk/HttpContent.h
index 71b055aaadc..2141c8beb8b 100644
--- a/samples/client/petstore/cpp-restsdk/HttpContent.h
+++ b/samples/client/petstore/cpp-restsdk/HttpContent.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/IHttpBody.h b/samples/client/petstore/cpp-restsdk/IHttpBody.h
index 88ce14a536d..b63ee0ce963 100644
--- a/samples/client/petstore/cpp-restsdk/IHttpBody.h
+++ b/samples/client/petstore/cpp-restsdk/IHttpBody.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/JsonBody.cpp b/samples/client/petstore/cpp-restsdk/JsonBody.cpp
index e3fbd7b340b..c9394f3a1af 100644
--- a/samples/client/petstore/cpp-restsdk/JsonBody.cpp
+++ b/samples/client/petstore/cpp-restsdk/JsonBody.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/JsonBody.h b/samples/client/petstore/cpp-restsdk/JsonBody.h
index 5ec9da11d70..b863e1a5984 100644
--- a/samples/client/petstore/cpp-restsdk/JsonBody.h
+++ b/samples/client/petstore/cpp-restsdk/JsonBody.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/ModelBase.cpp b/samples/client/petstore/cpp-restsdk/ModelBase.cpp
index d13dc7ac980..2008917d946 100644
--- a/samples/client/petstore/cpp-restsdk/ModelBase.cpp
+++ b/samples/client/petstore/cpp-restsdk/ModelBase.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/ModelBase.h b/samples/client/petstore/cpp-restsdk/ModelBase.h
index 6b9818617bc..d98ca65230c 100644
--- a/samples/client/petstore/cpp-restsdk/ModelBase.h
+++ b/samples/client/petstore/cpp-restsdk/ModelBase.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/MultipartFormData.cpp b/samples/client/petstore/cpp-restsdk/MultipartFormData.cpp
index fb9b11dfee1..b17730c4086 100644
--- a/samples/client/petstore/cpp-restsdk/MultipartFormData.cpp
+++ b/samples/client/petstore/cpp-restsdk/MultipartFormData.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/MultipartFormData.h b/samples/client/petstore/cpp-restsdk/MultipartFormData.h
index 166ada330ca..203112fb735 100644
--- a/samples/client/petstore/cpp-restsdk/MultipartFormData.h
+++ b/samples/client/petstore/cpp-restsdk/MultipartFormData.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
@@ -12,7 +12,7 @@
 /*
  * MultipartFormData.h
  *
- * This class represents a container for building a application/x-multipart-formdata requests.
+ * This class represents a container for building application/x-multipart-formdata requests.
  */
 
 #ifndef ORG_OPENAPITOOLS_CLIENT_MODEL_MultipartFormData_H_
diff --git a/samples/client/petstore/cpp-restsdk/Object.cpp b/samples/client/petstore/cpp-restsdk/Object.cpp
index 326ada285e9..c0f179a0e8b 100644
--- a/samples/client/petstore/cpp-restsdk/Object.cpp
+++ b/samples/client/petstore/cpp-restsdk/Object.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/Object.h b/samples/client/petstore/cpp-restsdk/Object.h
index ec9505e194b..109051fa4b3 100644
--- a/samples/client/petstore/cpp-restsdk/Object.h
+++ b/samples/client/petstore/cpp-restsdk/Object.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/api/PetApi.cpp b/samples/client/petstore/cpp-restsdk/api/PetApi.cpp
index 69b595fc629..5c7f06fc2b9 100644
--- a/samples/client/petstore/cpp-restsdk/api/PetApi.cpp
+++ b/samples/client/petstore/cpp-restsdk/api/PetApi.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/api/PetApi.h b/samples/client/petstore/cpp-restsdk/api/PetApi.h
index 01cc1f218bc..c0c1f7b63c2 100644
--- a/samples/client/petstore/cpp-restsdk/api/PetApi.h
+++ b/samples/client/petstore/cpp-restsdk/api/PetApi.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
@@ -35,11 +35,16 @@ namespace api {
 
 using namespace org::openapitools::client::model;
 
-class  PetApi
+
+
+class  PetApi 
 {
 public:
-    PetApi( std::shared_ptr<ApiClient> apiClient );
+
+    explicit PetApi( std::shared_ptr<ApiClient> apiClient );
+
     virtual ~PetApi();
+
     /// <summary>
     /// Add a new pet to the store
     /// </summary>
diff --git a/samples/client/petstore/cpp-restsdk/api/StoreApi.cpp b/samples/client/petstore/cpp-restsdk/api/StoreApi.cpp
index 18873055580..d466cb50539 100644
--- a/samples/client/petstore/cpp-restsdk/api/StoreApi.cpp
+++ b/samples/client/petstore/cpp-restsdk/api/StoreApi.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/api/StoreApi.h b/samples/client/petstore/cpp-restsdk/api/StoreApi.h
index 303345a8d7c..b7b033e04af 100644
--- a/samples/client/petstore/cpp-restsdk/api/StoreApi.h
+++ b/samples/client/petstore/cpp-restsdk/api/StoreApi.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
@@ -34,11 +34,16 @@ namespace api {
 
 using namespace org::openapitools::client::model;
 
-class  StoreApi
+
+
+class  StoreApi 
 {
 public:
-    StoreApi( std::shared_ptr<ApiClient> apiClient );
+
+    explicit StoreApi( std::shared_ptr<ApiClient> apiClient );
+
     virtual ~StoreApi();
+
     /// <summary>
     /// Delete purchase order by ID
     /// </summary>
diff --git a/samples/client/petstore/cpp-restsdk/api/UserApi.cpp b/samples/client/petstore/cpp-restsdk/api/UserApi.cpp
index 9c319adf023..c67d7afe658 100644
--- a/samples/client/petstore/cpp-restsdk/api/UserApi.cpp
+++ b/samples/client/petstore/cpp-restsdk/api/UserApi.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/api/UserApi.h b/samples/client/petstore/cpp-restsdk/api/UserApi.h
index 2b198b383a8..6be583c9a5b 100644
--- a/samples/client/petstore/cpp-restsdk/api/UserApi.h
+++ b/samples/client/petstore/cpp-restsdk/api/UserApi.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
@@ -34,11 +34,16 @@ namespace api {
 
 using namespace org::openapitools::client::model;
 
-class  UserApi
+
+
+class  UserApi 
 {
 public:
-    UserApi( std::shared_ptr<ApiClient> apiClient );
+
+    explicit UserApi( std::shared_ptr<ApiClient> apiClient );
+
     virtual ~UserApi();
+
     /// <summary>
     /// Create user
     /// </summary>
diff --git a/samples/client/petstore/cpp-restsdk/model/ApiResponse.cpp b/samples/client/petstore/cpp-restsdk/model/ApiResponse.cpp
index 1d8ebbac8b7..11a0cd4c0a6 100644
--- a/samples/client/petstore/cpp-restsdk/model/ApiResponse.cpp
+++ b/samples/client/petstore/cpp-restsdk/model/ApiResponse.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/model/ApiResponse.h b/samples/client/petstore/cpp-restsdk/model/ApiResponse.h
index 0514fcd38c9..2568511d517 100644
--- a/samples/client/petstore/cpp-restsdk/model/ApiResponse.h
+++ b/samples/client/petstore/cpp-restsdk/model/ApiResponse.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/model/Category.cpp b/samples/client/petstore/cpp-restsdk/model/Category.cpp
index 60f92843df0..0a2be543714 100644
--- a/samples/client/petstore/cpp-restsdk/model/Category.cpp
+++ b/samples/client/petstore/cpp-restsdk/model/Category.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/model/Category.h b/samples/client/petstore/cpp-restsdk/model/Category.h
index f77cf6c508b..45ae74a0f9f 100644
--- a/samples/client/petstore/cpp-restsdk/model/Category.h
+++ b/samples/client/petstore/cpp-restsdk/model/Category.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/model/Order.cpp b/samples/client/petstore/cpp-restsdk/model/Order.cpp
index f23fd13926c..610e66f4c63 100644
--- a/samples/client/petstore/cpp-restsdk/model/Order.cpp
+++ b/samples/client/petstore/cpp-restsdk/model/Order.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/model/Order.h b/samples/client/petstore/cpp-restsdk/model/Order.h
index 43893a44fa4..a9e5362f97e 100644
--- a/samples/client/petstore/cpp-restsdk/model/Order.h
+++ b/samples/client/petstore/cpp-restsdk/model/Order.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/model/Pet.cpp b/samples/client/petstore/cpp-restsdk/model/Pet.cpp
index 3c477013b10..f5be1d38434 100644
--- a/samples/client/petstore/cpp-restsdk/model/Pet.cpp
+++ b/samples/client/petstore/cpp-restsdk/model/Pet.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/model/Pet.h b/samples/client/petstore/cpp-restsdk/model/Pet.h
index d8392239766..a7a9f5dd4c8 100644
--- a/samples/client/petstore/cpp-restsdk/model/Pet.h
+++ b/samples/client/petstore/cpp-restsdk/model/Pet.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/model/Tag.cpp b/samples/client/petstore/cpp-restsdk/model/Tag.cpp
index 584a4b24cf5..2f7b3596aa4 100644
--- a/samples/client/petstore/cpp-restsdk/model/Tag.cpp
+++ b/samples/client/petstore/cpp-restsdk/model/Tag.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/model/Tag.h b/samples/client/petstore/cpp-restsdk/model/Tag.h
index 663fe05cfcc..cb0fcedef41 100644
--- a/samples/client/petstore/cpp-restsdk/model/Tag.h
+++ b/samples/client/petstore/cpp-restsdk/model/Tag.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/model/User.cpp b/samples/client/petstore/cpp-restsdk/model/User.cpp
index a06e9f5aa4b..2779424d4a8 100644
--- a/samples/client/petstore/cpp-restsdk/model/User.cpp
+++ b/samples/client/petstore/cpp-restsdk/model/User.cpp
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/client/petstore/cpp-restsdk/model/User.h b/samples/client/petstore/cpp-restsdk/model/User.h
index 0e5f4dc0844..f02e9ef719f 100644
--- a/samples/client/petstore/cpp-restsdk/model/User.h
+++ b/samples/client/petstore/cpp-restsdk/model/User.h
@@ -4,7 +4,7 @@
  *
  * OpenAPI spec version: 1.0.0
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 3.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 3.1.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */