diff --git a/modules/swagger-codegen/src/main/resources/swift3/APIHelper.mustache b/modules/swagger-codegen/src/main/resources/swift3/APIHelper.mustache
index b0bdb8a6c78..f5a6b477952 100644
--- a/modules/swagger-codegen/src/main/resources/swift3/APIHelper.mustache
+++ b/modules/swagger-codegen/src/main/resources/swift3/APIHelper.mustache
@@ -68,12 +68,8 @@ class APIHelper {
                 }
             }
             .flatMap { $0 }
-
-        if returnValues.count == 0 {
-            return nil
-        }
-
+ 
+        if returnValues.isEmpty { return nil }
         return returnValues
     }
-
 }
diff --git a/modules/swagger-codegen/src/main/resources/swift3/APIs.mustache b/modules/swagger-codegen/src/main/resources/swift3/APIs.mustache
index 340f5b66fd8..7529408ad5b 100644
--- a/modules/swagger-codegen/src/main/resources/swift3/APIs.mustache
+++ b/modules/swagger-codegen/src/main/resources/swift3/APIs.mustache
@@ -52,7 +52,7 @@ open class RequestBuilder<T> {
 
     open func addHeaders(_ aHeaders:[String:String]) {
         for (header, value) in aHeaders {
-            headers[header] = value
+            addHeader(name: header, value: value)
         }
     }
 
diff --git a/samples/client/petstore/swift3/default/PetstoreClient/Classes/Swaggers/APIHelper.swift b/samples/client/petstore/swift3/default/PetstoreClient/Classes/Swaggers/APIHelper.swift
index b0bdb8a6c78..f5a6b477952 100644
--- a/samples/client/petstore/swift3/default/PetstoreClient/Classes/Swaggers/APIHelper.swift
+++ b/samples/client/petstore/swift3/default/PetstoreClient/Classes/Swaggers/APIHelper.swift
@@ -68,12 +68,8 @@ class APIHelper {
                 }
             }
             .flatMap { $0 }
-
-        if returnValues.count == 0 {
-            return nil
-        }
-
+ 
+        if returnValues.isEmpty { return nil }
         return returnValues
     }
-
 }
diff --git a/samples/client/petstore/swift3/default/PetstoreClient/Classes/Swaggers/APIs.swift b/samples/client/petstore/swift3/default/PetstoreClient/Classes/Swaggers/APIs.swift
index 4edf5f440ba..6677fcf86e0 100644
--- a/samples/client/petstore/swift3/default/PetstoreClient/Classes/Swaggers/APIs.swift
+++ b/samples/client/petstore/swift3/default/PetstoreClient/Classes/Swaggers/APIs.swift
@@ -52,7 +52,7 @@ open class RequestBuilder<T> {
 
     open func addHeaders(_ aHeaders:[String:String]) {
         for (header, value) in aHeaders {
-            headers[header] = value
+            addHeader(name: header, value: value)
         }
     }
 
diff --git a/samples/client/petstore/swift3/promisekit/PetstoreClient/Classes/Swaggers/APIHelper.swift b/samples/client/petstore/swift3/promisekit/PetstoreClient/Classes/Swaggers/APIHelper.swift
index b0bdb8a6c78..f5a6b477952 100644
--- a/samples/client/petstore/swift3/promisekit/PetstoreClient/Classes/Swaggers/APIHelper.swift
+++ b/samples/client/petstore/swift3/promisekit/PetstoreClient/Classes/Swaggers/APIHelper.swift
@@ -68,12 +68,8 @@ class APIHelper {
                 }
             }
             .flatMap { $0 }
-
-        if returnValues.count == 0 {
-            return nil
-        }
-
+ 
+        if returnValues.isEmpty { return nil }
         return returnValues
     }
-
 }
diff --git a/samples/client/petstore/swift3/promisekit/PetstoreClient/Classes/Swaggers/APIs.swift b/samples/client/petstore/swift3/promisekit/PetstoreClient/Classes/Swaggers/APIs.swift
index 4edf5f440ba..6677fcf86e0 100644
--- a/samples/client/petstore/swift3/promisekit/PetstoreClient/Classes/Swaggers/APIs.swift
+++ b/samples/client/petstore/swift3/promisekit/PetstoreClient/Classes/Swaggers/APIs.swift
@@ -52,7 +52,7 @@ open class RequestBuilder<T> {
 
     open func addHeaders(_ aHeaders:[String:String]) {
         for (header, value) in aHeaders {
-            headers[header] = value
+            addHeader(name: header, value: value)
         }
     }
 
diff --git a/samples/client/petstore/swift3/rxswift/PetstoreClient/Classes/Swaggers/APIHelper.swift b/samples/client/petstore/swift3/rxswift/PetstoreClient/Classes/Swaggers/APIHelper.swift
index b0bdb8a6c78..f5a6b477952 100644
--- a/samples/client/petstore/swift3/rxswift/PetstoreClient/Classes/Swaggers/APIHelper.swift
+++ b/samples/client/petstore/swift3/rxswift/PetstoreClient/Classes/Swaggers/APIHelper.swift
@@ -68,12 +68,8 @@ class APIHelper {
                 }
             }
             .flatMap { $0 }
-
-        if returnValues.count == 0 {
-            return nil
-        }
-
+ 
+        if returnValues.isEmpty { return nil }
         return returnValues
     }
-
 }
diff --git a/samples/client/petstore/swift3/rxswift/PetstoreClient/Classes/Swaggers/APIs.swift b/samples/client/petstore/swift3/rxswift/PetstoreClient/Classes/Swaggers/APIs.swift
index 4edf5f440ba..6677fcf86e0 100644
--- a/samples/client/petstore/swift3/rxswift/PetstoreClient/Classes/Swaggers/APIs.swift
+++ b/samples/client/petstore/swift3/rxswift/PetstoreClient/Classes/Swaggers/APIs.swift
@@ -52,7 +52,7 @@ open class RequestBuilder<T> {
 
     open func addHeaders(_ aHeaders:[String:String]) {
         for (header, value) in aHeaders {
-            headers[header] = value
+            addHeader(name: header, value: value)
         }
     }
 
diff --git a/samples/client/petstore/swift3/unwraprequired/PetstoreClient/Classes/Swaggers/APIHelper.swift b/samples/client/petstore/swift3/unwraprequired/PetstoreClient/Classes/Swaggers/APIHelper.swift
index b0bdb8a6c78..f5a6b477952 100644
--- a/samples/client/petstore/swift3/unwraprequired/PetstoreClient/Classes/Swaggers/APIHelper.swift
+++ b/samples/client/petstore/swift3/unwraprequired/PetstoreClient/Classes/Swaggers/APIHelper.swift
@@ -68,12 +68,8 @@ class APIHelper {
                 }
             }
             .flatMap { $0 }
-
-        if returnValues.count == 0 {
-            return nil
-        }
-
+ 
+        if returnValues.isEmpty { return nil }
         return returnValues
     }
-
 }
diff --git a/samples/client/petstore/swift3/unwraprequired/PetstoreClient/Classes/Swaggers/APIs.swift b/samples/client/petstore/swift3/unwraprequired/PetstoreClient/Classes/Swaggers/APIs.swift
index 4edf5f440ba..6677fcf86e0 100644
--- a/samples/client/petstore/swift3/unwraprequired/PetstoreClient/Classes/Swaggers/APIs.swift
+++ b/samples/client/petstore/swift3/unwraprequired/PetstoreClient/Classes/Swaggers/APIs.swift
@@ -52,7 +52,7 @@ open class RequestBuilder<T> {
 
     open func addHeaders(_ aHeaders:[String:String]) {
         for (header, value) in aHeaders {
-            headers[header] = value
+            addHeader(name: header, value: value)
         }
     }