[Java][okhttp-gson] Add option to employ builders for API requests (#1341)

* Generate APIs that use the builder pattern

* Add option to use builders for API requests

* Fix template spacing

* Add new sample-generation script and generated samples

* Update docs

* Add new sample-generation script for Windows

* Replace config option with vendor extension

* Remove useBuildersForApiRequests config option

* Remove builders sample-generation scripts

* Replace config option with vendor extension in api_test template

* Remove okhttp-gson-requestBuilders sample

* Rename x-builders-for-api-requests to x-group-parameters

* Add modified api_doc.mustache under okhttp-gson resources

* Add modified README.mustache under okhttp-gson resources

* Update petstore samples

* Fix FakeApiTest.java in petstore samples

* Add whitespace to rerun checks

* Remove whitespace to rerun tests

* Fix FakeApiTest.java in parcelable petstore sample

* Update versions in samples

* Update versions in samples

modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/README.mustache

@@ -0,0 +1,169 @@
+# {{artifactId}}
+
+{{appName}}
+- API version: {{appVersion}}
+{{^hideGenerationTimestamp}}
+  - Build date: {{generatedDate}}
+{{/hideGenerationTimestamp}}
+
+{{#appDescription}}{{{appDescription}}}{{/appDescription}}
+
+{{#infoUrl}}
+  For more information, please visit [{{{infoUrl}}}]({{{infoUrl}}})
+{{/infoUrl}}
+
+*Automatically generated by the [OpenAPI Generator](https://openapi-generator.tech)*
+
+
+## Requirements
+
+Building the API client library requires:
+1. Java {{#supportJava6}}1.6{{/supportJava6}}{{^supportJava6}}{{#java8}}1.8{{/java8}}{{^java8}}1.7{{/java8}}{{/supportJava6}}+
+2. Maven/Gradle
+
+## Installation
+
+To install the API client library to your local Maven repository, simply execute:
+
+```shell
+mvn clean install
+```
+
+To deploy it to a remote Maven repository instead, configure the settings of the repository and execute:
+
+```shell
+mvn clean deploy
+```
+
+Refer to the [OSSRH Guide](http://central.sonatype.org/pages/ossrh-guide.html) for more information.
+
+### Maven users
+
+Add this dependency to your project's POM:
+
+```xml
+<dependency>
+  <groupId>{{{groupId}}}</groupId>
+  <artifactId>{{{artifactId}}}</artifactId>
+  <version>{{{artifactVersion}}}</version>
+  <scope>compile</scope>
+</dependency>
+```
+
+### Gradle users
+
+Add this dependency to your project's build file:
+
+```groovy
+compile "{{{groupId}}}:{{{artifactId}}}:{{{artifactVersion}}}"
+```
+
+### Others
+
+At first generate the JAR by executing:
+
+```shell
+mvn clean package
+```
+
+Then manually install the following JARs:
+
+* `target/{{{artifactId}}}-{{{artifactVersion}}}.jar`
+* `target/lib/*.jar`
+
+## Getting Started
+
+Please follow the [installation](#installation) instruction and execute the following Java code:
+
+```java
+{{#apiInfo}}{{#apis}}{{#-first}}{{#operations}}{{#operation}}{{#-first}}
+import {{{invokerPackage}}}.*;
+import {{{invokerPackage}}}.auth.*;
+import {{{modelPackage}}}.*;
+import {{{package}}}.{{{classname}}};
+
+import java.io.File;
+import java.util.*;
+
+public class {{{classname}}}Example {
+
+    public static void main(String[] args) {
+        {{#hasAuthMethods}}ApiClient defaultClient = Configuration.getDefaultApiClient();
+        {{#authMethods}}{{#isBasic}}
+        // Configure HTTP basic authorization: {{{name}}}
+        HttpBasicAuth {{{name}}} = (HttpBasicAuth) defaultClient.getAuthentication("{{{name}}}");
+        {{{name}}}.setUsername("YOUR USERNAME");
+        {{{name}}}.setPassword("YOUR PASSWORD");{{/isBasic}}{{#isApiKey}}
+        // Configure API key authorization: {{{name}}}
+        ApiKeyAuth {{{name}}} = (ApiKeyAuth) defaultClient.getAuthentication("{{{name}}}");
+        {{{name}}}.setApiKey("YOUR API KEY");
+        // Uncomment the following line to set a prefix for the API key, e.g. "Token" (defaults to null)
+        //{{{name}}}.setApiKeyPrefix("Token");{{/isApiKey}}{{#isOAuth}}
+        // Configure OAuth2 access token for authorization: {{{name}}}
+        OAuth {{{name}}} = (OAuth) defaultClient.getAuthentication("{{{name}}}");
+        {{{name}}}.setAccessToken("YOUR ACCESS TOKEN");{{/isOAuth}}
+        {{/authMethods}}
+        {{/hasAuthMethods}}
+
+        {{{classname}}} apiInstance = new {{{classname}}}();
+        {{#allParams}}
+        {{{dataType}}} {{{paramName}}} = {{{example}}}; // {{{dataType}}} | {{{description}}}
+        {{/allParams}}
+        try {
+            {{#returnType}}{{{returnType}}} result = {{/returnType}}apiInstance.{{{operationId}}}{{^vendorExtensions.x-group-parameters}}({{#allParams}}{{{paramName}}}{{#hasMore}}, {{/hasMore}}{{/allParams}});{{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}({{#requiredParams}}{{{paramName}}}{{#hasMore}}, {{/hasMore}}{{/requiredParams}}){{#optionalParams}}
+                    .{{{paramName}}}({{{paramName}}}){{/optionalParams}}
+                    .execute();{{/vendorExtensions.x-group-parameters}}{{#returnType}}
+            System.out.println(result);{{/returnType}}
+        } catch (ApiException e) {
+            System.err.println("Exception when calling {{{classname}}}#{{{operationId}}}");
+            e.printStackTrace();
+        }
+    }
+}
+{{/-first}}{{/operation}}{{/operations}}{{/-first}}{{/apis}}{{/apiInfo}}
+```
+
+## Documentation for API Endpoints
+
+All URIs are relative to *{{basePath}}*
+
+Class | Method | HTTP request | Description
+------------ | ------------- | ------------- | -------------
+{{#apiInfo}}{{#apis}}{{#operations}}{{#operation}}*{{classname}}* | [**{{operationId}}**]({{apiDocPath}}{{classname}}.md#{{operationId}}) | **{{httpMethod}}** {{path}} | {{#summary}}{{summary}}{{/summary}}
+{{/operation}}{{/operations}}{{/apis}}{{/apiInfo}}
+
+## Documentation for Models
+
+{{#models}}{{#model}} - [{{classname}}]({{modelDocPath}}{{classname}}.md)
+{{/model}}{{/models}}
+
+## Documentation for Authorization
+
+{{^authMethods}}All endpoints do not require authorization.
+{{/authMethods}}Authentication schemes defined for the API:
+{{#authMethods}}### {{name}}
+
+{{#isApiKey}}- **Type**: API key
+- **API key parameter name**: {{keyParamName}}
+- **Location**: {{#isKeyInQuery}}URL query string{{/isKeyInQuery}}{{#isKeyInHeader}}HTTP header{{/isKeyInHeader}}
+{{/isApiKey}}
+{{#isBasic}}- **Type**: HTTP basic authentication
+{{/isBasic}}
+{{#isOAuth}}- **Type**: OAuth
+- **Flow**: {{flow}}
+- **Authorization URL**: {{authorizationUrl}}
+- **Scopes**: {{^scopes}}N/A{{/scopes}}
+{{#scopes}}  - {{scope}}: {{description}}
+{{/scopes}}
+{{/isOAuth}}
+
+{{/authMethods}}
+
+## Recommendation
+
+It's recommended to create an instance of `ApiClient` per thread in a multithreaded environment to avoid any potential issues.
+
+## Author
+
+{{#apiInfo}}{{#apis}}{{^hasMore}}{{infoEmail}}
+{{/hasMore}}{{/apis}}{{/apiInfo}}

modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/api.mustache

@@ -63,7 +63,7 @@ public class {{classname}} {
     }
 
     {{#operation}}
-    /**
+    {{^vendorExtensions.x-group-parameters}}/**
      * Build call for {{operationId}}{{#allParams}}
      * @param {{paramName}} {{description}}{{#required}} (required){{/required}}{{^required}} (optional{{^isContainer}}{{#defaultValue}}, default to {{.}}{{/defaultValue}}{{/isContainer}}){{/required}}{{/allParams}}
      * @param progressListener Progress listener
@@ -81,7 +81,7 @@ public class {{classname}} {
     {{#isDeprecated}}
     @Deprecated
     {{/isDeprecated}}
-    public com.squareup.okhttp.Call {{operationId}}Call({{#allParams}}{{{dataType}}} {{paramName}}, {{/allParams}}final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
+    public{{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}private{{/vendorExtensions.x-group-parameters}} com.squareup.okhttp.Call {{operationId}}Call({{#allParams}}{{{dataType}}} {{paramName}}, {{/allParams}}final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
         Object {{localVariablePrefix}}localVarPostBody = {{#bodyParam}}{{paramName}}{{/bodyParam}}{{^bodyParam}}new Object(){{/bodyParam}};
 
         // create path and map variables
@@ -185,6 +185,7 @@ public class {{classname}} {
         {{/performBeanValidation}}
     }
 
+    {{^vendorExtensions.x-group-parameters}}
     /**
      * {{summary}}
      * {{notes}}{{#allParams}}
@@ -206,8 +207,9 @@ public class {{classname}} {
         {{#returnType}}ApiResponse<{{{returnType}}}> {{localVariablePrefix}}resp = {{/returnType}}{{operationId}}WithHttpInfo({{#allParams}}{{paramName}}{{#hasMore}}, {{/hasMore}}{{/allParams}});{{#returnType}}
         return {{localVariablePrefix}}resp.getData();{{/returnType}}
     }
+    {{/vendorExtensions.x-group-parameters}}
 
-    /**
+    {{^vendorExtensions.x-group-parameters}}/**
      * {{summary}}
      * {{notes}}{{#allParams}}
      * @param {{paramName}} {{description}}{{#required}} (required){{/required}}{{^required}} (optional{{^isContainer}}{{#defaultValue}}, default to {{.}}{{/defaultValue}}{{/isContainer}}){{/required}}{{/allParams}}
@@ -224,13 +226,13 @@ public class {{classname}} {
     {{#isDeprecated}}
     @Deprecated
     {{/isDeprecated}}
-    public ApiResponse<{{#returnType}}{{{returnType}}}{{/returnType}}{{^returnType}}Void{{/returnType}}> {{operationId}}WithHttpInfo({{#allParams}}{{#useBeanValidation}}{{>beanValidationQueryParams}}{{/useBeanValidation}}{{{dataType}}} {{paramName}}{{#hasMore}}, {{/hasMore}}{{/allParams}}) throws ApiException {
+    public{{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}private{{/vendorExtensions.x-group-parameters}} ApiResponse<{{#returnType}}{{{returnType}}}{{/returnType}}{{^returnType}}Void{{/returnType}}> {{operationId}}WithHttpInfo({{#allParams}}{{#useBeanValidation}}{{>beanValidationQueryParams}}{{/useBeanValidation}}{{{dataType}}} {{paramName}}{{#hasMore}}, {{/hasMore}}{{/allParams}}) throws ApiException {
         com.squareup.okhttp.Call {{localVariablePrefix}}call = {{operationId}}ValidateBeforeCall({{#allParams}}{{paramName}}, {{/allParams}}null, null);
         {{#returnType}}Type {{localVariablePrefix}}localVarReturnType = new TypeToken<{{{returnType}}}>(){}.getType();
         return {{localVariablePrefix}}apiClient.execute({{localVariablePrefix}}call, {{localVariablePrefix}}localVarReturnType);{{/returnType}}{{^returnType}}return {{localVariablePrefix}}apiClient.execute({{localVariablePrefix}}call);{{/returnType}}
     }
 
-    /**
+    {{^vendorExtensions.x-group-parameters}}/**
      * {{summary}} (asynchronously)
      * {{notes}}{{#allParams}}
      * @param {{paramName}} {{description}}{{#required}} (required){{/required}}{{^required}} (optional{{^isContainer}}{{#defaultValue}}, default to {{.}}{{/defaultValue}}{{/isContainer}}){{/required}}{{/allParams}}
@@ -248,7 +250,7 @@ public class {{classname}} {
     {{#isDeprecated}}
     @Deprecated
     {{/isDeprecated}}
-    public com.squareup.okhttp.Call {{operationId}}Async({{#allParams}}{{{dataType}}} {{paramName}}, {{/allParams}}final ApiCallback<{{#returnType}}{{{returnType}}}{{/returnType}}{{^returnType}}Void{{/returnType}}> {{localVariablePrefix}}callback) throws ApiException {
+    public{{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}private{{/vendorExtensions.x-group-parameters}} com.squareup.okhttp.Call {{operationId}}Async({{#allParams}}{{{dataType}}} {{paramName}}, {{/allParams}}final ApiCallback<{{#returnType}}{{{returnType}}}{{/returnType}}{{^returnType}}Void{{/returnType}}> {{localVariablePrefix}}callback) throws ApiException {
 
         ProgressResponseBody.ProgressListener progressListener = null;
         ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
@@ -274,6 +276,119 @@ public class {{classname}} {
         {{localVariablePrefix}}apiClient.executeAsync({{localVariablePrefix}}call, {{localVariablePrefix}}localVarReturnType, {{localVariablePrefix}}callback);{{/returnType}}{{^returnType}}{{localVariablePrefix}}apiClient.executeAsync({{localVariablePrefix}}call, {{localVariablePrefix}}callback);{{/returnType}}
         return {{localVariablePrefix}}call;
     }
+    {{#vendorExtensions.x-group-parameters}}
+
+    public class API{{operationId}}Request {
+        {{#requiredParams}}
+        private final {{{dataType}}} {{localVariablePrefix}}{{paramName}};
+        {{/requiredParams}}
+        {{#optionalParams}}
+        private {{{dataType}}} {{localVariablePrefix}}{{paramName}};
+        {{/optionalParams}}
+
+        private API{{operationId}}Request({{#requiredParams}}{{{dataType}}} {{paramName}}{{#hasMore}}, {{/hasMore}}{{/requiredParams}}) {
+            {{#requiredParams}}
+            this.{{localVariablePrefix}}{{paramName}} = {{paramName}};
+            {{/requiredParams}}
+        }
+
+        {{#optionalParams}}
+        /**
+         * Set {{paramName}}
+         * @param {{paramName}} {{description}} (optional{{^isContainer}}{{#defaultValue}}, default to {{.}}{{/defaultValue}}{{/isContainer}})
+         * @return API{{operationId}}Request
+         */
+        public API{{operationId}}Request {{paramName}}({{{dataType}}} {{paramName}}) {
+            this.{{localVariablePrefix}}{{paramName}} = {{paramName}};
+            return this;
+        }
+
+        {{/optionalParams}}
+        /**
+         * Build call for {{operationId}}
+         * @param progressListener Progress listener
+         * @param progressRequestListener Progress request listener
+         * @return Call to execute
+         * @throws ApiException If fail to serialize the request body object
+         {{#isDeprecated}}
+         * @deprecated
+         {{/isDeprecated}}
+         */
+        {{#isDeprecated}}
+        @Deprecated
+        {{/isDeprecated}}
+        public com.squareup.okhttp.Call buildCall(final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
+            return {{operationId}}Call({{#allParams}}{{localVariablePrefix}}{{paramName}}, {{/allParams}}progressListener, progressRequestListener);
+        }
+
+        /**
+         * Execute {{operationId}} request{{#returnType}}
+         * @return {{returnType}}{{/returnType}}
+         * @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body
+         {{#isDeprecated}}
+         * @deprecated
+         {{/isDeprecated}}
+         */
+        {{#isDeprecated}}
+        @Deprecated
+        {{/isDeprecated}}
+        public {{#returnType}}{{{returnType}}}{{/returnType}}{{^returnType}}void{{/returnType}} execute() throws ApiException {
+            {{#returnType}}ApiResponse<{{{returnType}}}> {{localVariablePrefix}}resp = {{/returnType}}{{operationId}}WithHttpInfo({{#allParams}}{{paramName}}{{#hasMore}}, {{/hasMore}}{{/allParams}});{{#returnType}}
+            return {{localVariablePrefix}}resp.getData();{{/returnType}}
+        }
+
+        /**
+         * Execute {{operationId}} request with HTTP info returned
+         * @return ApiResponse&lt;{{#returnType}}{{returnType}}{{/returnType}}{{^returnType}}Void{{/returnType}}&gt;
+         * @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body
+         {{#isDeprecated}}
+         * @deprecated
+         {{/isDeprecated}}
+         */
+        {{#isDeprecated}}
+        @Deprecated
+        {{/isDeprecated}}
+        public ApiResponse<{{#returnType}}{{{returnType}}}{{/returnType}}{{^returnType}}Void{{/returnType}}> executeWithHttpInfo() throws ApiException {
+            return {{operationId}}WithHttpInfo({{#allParams}}{{localVariablePrefix}}{{paramName}}{{#hasMore}}, {{/hasMore}}{{/allParams}});
+        }
+
+        /**
+         * Execute {{operationId}} request (asynchronously)
+         * @param callback The callback to be executed when the API call finishes
+         * @return The request call
+         * @throws ApiException If fail to process the API call, e.g. serializing the request body object
+         {{#isDeprecated}}
+         * @deprecated
+         {{/isDeprecated}}
+         */
+        {{#isDeprecated}}
+        @Deprecated
+        {{/isDeprecated}}
+        public com.squareup.okhttp.Call executeAsync(final ApiCallback<{{#returnType}}{{{returnType}}}{{/returnType}}{{^returnType}}Void{{/returnType}}> callback) throws ApiException {
+            return {{operationId}}Async({{#allParams}}{{localVariablePrefix}}{{paramName}}, {{/allParams}}callback);
+        }
+    }
+
+    /**
+     * {{summary}}
+     * {{notes}}{{#requiredParams}}
+     * @param {{paramName}} {{description}} (required){{/requiredParams}}
+     * @return API{{operationId}}Request
+     {{#isDeprecated}}
+     * @deprecated
+     {{/isDeprecated}}
+        {{#externalDocs}}
+     * {{description}}
+     * @see <a href="{{url}}">{{summary}} Documentation</a>
+        {{/externalDocs}}
+     */
+    {{#isDeprecated}}
+    @Deprecated
+    {{/isDeprecated}}
+    public API{{operationId}}Request {{operationId}}({{#requiredParams}}{{{dataType}}} {{paramName}}{{#hasMore}}, {{/hasMore}}{{/requiredParams}}) {
+        return new API{{operationId}}Request({{#requiredParams}}{{paramName}}{{#hasMore}}, {{/hasMore}}{{/requiredParams}});
+    }
+    {{/vendorExtensions.x-group-parameters}}
     {{/operation}}
 }
 {{/operations}}

modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/api_doc.mustache

@@ -0,0 +1,85 @@
+# {{classname}}{{#description}}
+{{description}}{{/description}}
+
+All URIs are relative to *{{basePath}}*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+{{#operations}}{{#operation}}[**{{operationId}}**]({{classname}}.md#{{operationId}}) | **{{httpMethod}}** {{path}} | {{#summary}}{{summary}}{{/summary}}
+{{/operation}}{{/operations}}
+
+{{#operations}}
+{{#operation}}
+<a name="{{operationId}}"></a>
+# **{{operationId}}**{{^vendorExtensions.x-group-parameters}}
+> {{#returnType}}{{returnType}} {{/returnType}}{{operationId}}({{#allParams}}{{{paramName}}}{{#hasMore}}, {{/hasMore}}{{/allParams}}){{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}
+> {{#returnType}}{{returnType}} {{/returnType}}{{operationId}}({{#requiredParams}}{{paramName}}{{#hasMore}}, {{/hasMore}}{{/requiredParams}}){{#optionalParams}}.{{paramName}}({{paramName}}){{/optionalParams}}.execute();{{/vendorExtensions.x-group-parameters}}
+
+{{summary}}{{#notes}}
+
+{{notes}}{{/notes}}
+
+### Example
+```java
+// Import classes:{{#hasAuthMethods}}
+//import {{{invokerPackage}}}.ApiClient;{{/hasAuthMethods}}
+//import {{{invokerPackage}}}.ApiException;{{#hasAuthMethods}}
+//import {{{invokerPackage}}}.Configuration;
+//import {{{invokerPackage}}}.auth.*;{{/hasAuthMethods}}
+//import {{{package}}}.{{{classname}}};
+
+{{#hasAuthMethods}}
+ApiClient defaultClient = Configuration.getDefaultApiClient();
+{{#authMethods}}{{#isBasic}}
+// Configure HTTP basic authorization: {{{name}}}
+HttpBasicAuth {{{name}}} = (HttpBasicAuth) defaultClient.getAuthentication("{{{name}}}");
+{{{name}}}.setUsername("YOUR USERNAME");
+{{{name}}}.setPassword("YOUR PASSWORD");{{/isBasic}}{{#isApiKey}}
+// Configure API key authorization: {{{name}}}
+ApiKeyAuth {{{name}}} = (ApiKeyAuth) defaultClient.getAuthentication("{{{name}}}");
+{{{name}}}.setApiKey("YOUR API KEY");
+// Uncomment the following line to set a prefix for the API key, e.g. "Token" (defaults to null)
+//{{{name}}}.setApiKeyPrefix("Token");{{/isApiKey}}{{#isOAuth}}
+// Configure OAuth2 access token for authorization: {{{name}}}
+OAuth {{{name}}} = (OAuth) defaultClient.getAuthentication("{{{name}}}");
+{{{name}}}.setAccessToken("YOUR ACCESS TOKEN");{{/isOAuth}}
+{{/authMethods}}
+{{/hasAuthMethods}}
+
+{{{classname}}} apiInstance = new {{{classname}}}();
+{{#allParams}}
+{{{dataType}}} {{{paramName}}} = {{{example}}}; // {{{dataType}}} | {{{description}}}
+{{/allParams}}
+try {
+    {{#returnType}}{{{returnType}}} result = {{/returnType}}apiInstance.{{{operationId}}}{{^vendorExtensions.x-group-parameters}}({{#allParams}}{{{paramName}}}{{#hasMore}}, {{/hasMore}}{{/allParams}});{{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}({{#requiredParams}}{{{paramName}}}{{#hasMore}}, {{/hasMore}}{{/requiredParams}}){{#optionalParams}}
+            .{{{paramName}}}({{{paramName}}}){{/optionalParams}}
+            .execute();{{/vendorExtensions.x-group-parameters}}{{#returnType}}
+    System.out.println(result);{{/returnType}}
+} catch (ApiException e) {
+    System.err.println("Exception when calling {{{classname}}}#{{{operationId}}}");
+    e.printStackTrace();
+}
+```
+
+### Parameters
+{{^allParams}}This endpoint does not need any parameter.{{/allParams}}{{#allParams}}{{#-last}}
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------{{/-last}}{{/allParams}}
+{{#allParams}} **{{paramName}}** | {{#isPrimitiveType}}**{{dataType}}**{{/isPrimitiveType}}{{^isPrimitiveType}}{{#isFile}}**{{dataType}}**{{/isFile}}{{^isFile}}[**{{dataType}}**]({{baseType}}.md){{/isFile}}{{/isPrimitiveType}}| {{description}} |{{^required}} [optional]{{/required}}{{^isContainer}}{{#defaultValue}} [default to {{defaultValue}}]{{/defaultValue}}{{/isContainer}}{{#allowableValues}} [enum: {{#values}}{{{.}}}{{^-last}}, {{/-last}}{{/values}}]{{/allowableValues}}
+{{/allParams}}
+
+### Return type
+
+{{#returnType}}{{#returnTypeIsPrimitive}}**{{returnType}}**{{/returnTypeIsPrimitive}}{{^returnTypeIsPrimitive}}[**{{returnType}}**]({{returnBaseType}}.md){{/returnTypeIsPrimitive}}{{/returnType}}{{^returnType}}null (empty response body){{/returnType}}
+
+### Authorization
+
+{{^authMethods}}No authorization required{{/authMethods}}{{#authMethods}}[{{name}}](../README.md#{{name}}){{^-last}}, {{/-last}}{{/authMethods}}
+
+### HTTP request headers
+
+ - **Content-Type**: {{#consumes}}{{{mediaType}}}{{#hasMore}}, {{/hasMore}}{{/consumes}}{{^consumes}}Not defined{{/consumes}}
+ - **Accept**: {{#produces}}{{{mediaType}}}{{#hasMore}}, {{/hasMore}}{{/produces}}{{^produces}}Not defined{{/produces}}
+
+{{/operation}}
+{{/operations}}

modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/api_test.mustache

@@ -0,0 +1,47 @@
+{{>licenseInfo}}
+
+package {{package}};
+
+import {{invokerPackage}}.ApiException;
+{{#imports}}import {{import}};
+{{/imports}}
+import org.junit.Test;
+import org.junit.Ignore;
+
+{{^fullJavaUtil}}
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+{{/fullJavaUtil}}
+
+/**
+ * API tests for {{classname}}
+ */
+@Ignore
+public class {{classname}}Test {
+
+    private final {{classname}} api = new {{classname}}();
+
+    {{#operations}}{{#operation}}
+    /**
+     * {{summary}}
+     *
+     * {{notes}}
+     *
+     * @throws ApiException
+     *          if the Api call fails
+     */
+    @Test
+    public void {{operationId}}Test() throws ApiException {
+        {{#allParams}}
+        {{{dataType}}} {{paramName}} = null;
+        {{/allParams}}
+        {{#returnType}}{{{returnType}}} response = {{/returnType}}api.{{operationId}}{{^vendorExtensions.x-group-parameters}}({{#allParams}}{{paramName}}{{#hasMore}}, {{/hasMore}}{{/allParams}});{{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}({{#requiredParams}}{{paramName}}{{#hasMore}}, {{/hasMore}}{{/requiredParams}}){{#optionalParams}}
+                .{{paramName}}({{paramName}}){{/optionalParams}}
+                .execute();{{/vendorExtensions.x-group-parameters}}
+
+        // TODO: test validations
+    }
+    {{/operation}}{{/operations}}
+}

samples/client/petstore-security-test/java/okhttp-gson/.openapi-generator/VERSION

@@ -1 +1 @@
-3.3.2-SNAPSHOT
+3.3.3

samples/client/petstore/java/okhttp-gson-parcelableModel/docs/FakeApi.md

@@ -470,7 +470,7 @@ No authorization required
 
 <a name="testGroupParameters"></a>
 # **testGroupParameters**
-> testGroupParameters(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group)
+> testGroupParameters(requiredStringGroup, requiredBooleanGroup, requiredInt64Group).stringGroup(stringGroup).booleanGroup(booleanGroup).int64Group(int64Group).execute();
 
 Fake endpoint to test group parameters (optional)
 
@@ -491,7 +491,11 @@ Integer stringGroup = 56; // Integer | String in group parameters
 Boolean booleanGroup = true; // Boolean | Boolean in group parameters
 Long int64Group = 56L; // Long | Integer in group parameters
 try {
-    apiInstance.testGroupParameters(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group);
+    apiInstance.testGroupParameters(requiredStringGroup, requiredBooleanGroup, requiredInt64Group)
+            .stringGroup(stringGroup)
+            .booleanGroup(booleanGroup)
+            .int64Group(int64Group)
+            .execute();
 } catch (ApiException e) {
     System.err.println("Exception when calling FakeApi#testGroupParameters");
     e.printStackTrace();

samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/api/FakeApi.java

@@ -1305,20 +1305,7 @@ public class FakeApi {
         apiClient.executeAsync(call, callback);
         return call;
     }
-    /**
+    private com.squareup.okhttp.Call testGroupParametersCall(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
-     * Build call for testGroupParameters
-     * @param requiredStringGroup Required String in group parameters (required)
-     * @param requiredBooleanGroup Required Boolean in group parameters (required)
-     * @param requiredInt64Group Required Integer in group parameters (required)
-     * @param stringGroup String in group parameters (optional)
-     * @param booleanGroup Boolean in group parameters (optional)
-     * @param int64Group Integer in group parameters (optional)
-     * @param progressListener Progress listener
-     * @param progressRequestListener Progress request listener
-     * @return Call to execute
-     * @throws ApiException If fail to serialize the request body object
-     */
-    public com.squareup.okhttp.Call testGroupParametersCall(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
         Object localVarPostBody = new Object();
 
         // create path and map variables
@@ -1406,52 +1393,13 @@ public class FakeApi {
 
     }
 
-    /**
-     * Fake endpoint to test group parameters (optional)
-     * Fake endpoint to test group parameters (optional)
-     * @param requiredStringGroup Required String in group parameters (required)
-     * @param requiredBooleanGroup Required Boolean in group parameters (required)
-     * @param requiredInt64Group Required Integer in group parameters (required)
-     * @param stringGroup String in group parameters (optional)
-     * @param booleanGroup Boolean in group parameters (optional)
-     * @param int64Group Integer in group parameters (optional)
-     * @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body
-     */
-    public void testGroupParameters(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group) throws ApiException {
-        testGroupParametersWithHttpInfo(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group);
-    }
 
-    /**
+    private ApiResponse<Void> testGroupParametersWithHttpInfo(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group) throws ApiException {
-     * Fake endpoint to test group parameters (optional)
-     * Fake endpoint to test group parameters (optional)
-     * @param requiredStringGroup Required String in group parameters (required)
-     * @param requiredBooleanGroup Required Boolean in group parameters (required)
-     * @param requiredInt64Group Required Integer in group parameters (required)
-     * @param stringGroup String in group parameters (optional)
-     * @param booleanGroup Boolean in group parameters (optional)
-     * @param int64Group Integer in group parameters (optional)
-     * @return ApiResponse&lt;Void&gt;
-     * @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body
-     */
-    public ApiResponse<Void> testGroupParametersWithHttpInfo(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group) throws ApiException {
         com.squareup.okhttp.Call call = testGroupParametersValidateBeforeCall(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group, null, null);
         return apiClient.execute(call);
     }
 
-    /**
+    private com.squareup.okhttp.Call testGroupParametersAsync(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group, final ApiCallback<Void> callback) throws ApiException {
-     * Fake endpoint to test group parameters (optional) (asynchronously)
-     * Fake endpoint to test group parameters (optional)
-     * @param requiredStringGroup Required String in group parameters (required)
-     * @param requiredBooleanGroup Required Boolean in group parameters (required)
-     * @param requiredInt64Group Required Integer in group parameters (required)
-     * @param stringGroup String in group parameters (optional)
-     * @param booleanGroup Boolean in group parameters (optional)
-     * @param int64Group Integer in group parameters (optional)
-     * @param callback The callback to be executed when the API call finishes
-     * @return The request call
-     * @throws ApiException If fail to process the API call, e.g. serializing the request body object
-     */
-    public com.squareup.okhttp.Call testGroupParametersAsync(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group, final ApiCallback<Void> callback) throws ApiException {
 
         ProgressResponseBody.ProgressListener progressListener = null;
         ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
@@ -1476,6 +1424,101 @@ public class FakeApi {
         apiClient.executeAsync(call, callback);
         return call;
     }
+
+    public class APItestGroupParametersRequest {
+        private final Integer requiredStringGroup;
+        private final Boolean requiredBooleanGroup;
+        private final Long requiredInt64Group;
+        private Integer stringGroup;
+        private Boolean booleanGroup;
+        private Long int64Group;
+
+        private APItestGroupParametersRequest(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group) {
+            this.requiredStringGroup = requiredStringGroup;
+            this.requiredBooleanGroup = requiredBooleanGroup;
+            this.requiredInt64Group = requiredInt64Group;
+        }
+
+        /**
+         * Set stringGroup
+         * @param stringGroup String in group parameters (optional)
+         * @return APItestGroupParametersRequest
+         */
+        public APItestGroupParametersRequest stringGroup(Integer stringGroup) {
+            this.stringGroup = stringGroup;
+            return this;
+        }
+
+        /**
+         * Set booleanGroup
+         * @param booleanGroup Boolean in group parameters (optional)
+         * @return APItestGroupParametersRequest
+         */
+        public APItestGroupParametersRequest booleanGroup(Boolean booleanGroup) {
+            this.booleanGroup = booleanGroup;
+            return this;
+        }
+
+        /**
+         * Set int64Group
+         * @param int64Group Integer in group parameters (optional)
+         * @return APItestGroupParametersRequest
+         */
+        public APItestGroupParametersRequest int64Group(Long int64Group) {
+            this.int64Group = int64Group;
+            return this;
+        }
+
+        /**
+         * Build call for testGroupParameters
+         * @param progressListener Progress listener
+         * @param progressRequestListener Progress request listener
+         * @return Call to execute
+         * @throws ApiException If fail to serialize the request body object
+         */
+        public com.squareup.okhttp.Call buildCall(final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
+            return testGroupParametersCall(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group, progressListener, progressRequestListener);
+        }
+
+        /**
+         * Execute testGroupParameters request
+         * @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body
+         */
+        public void execute() throws ApiException {
+            testGroupParametersWithHttpInfo(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group);
+        }
+
+        /**
+         * Execute testGroupParameters request with HTTP info returned
+         * @return ApiResponse&lt;Void&gt;
+         * @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body
+         */
+        public ApiResponse<Void> executeWithHttpInfo() throws ApiException {
+            return testGroupParametersWithHttpInfo(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group);
+        }
+
+        /**
+         * Execute testGroupParameters request (asynchronously)
+         * @param callback The callback to be executed when the API call finishes
+         * @return The request call
+         * @throws ApiException If fail to process the API call, e.g. serializing the request body object
+         */
+        public com.squareup.okhttp.Call executeAsync(final ApiCallback<Void> callback) throws ApiException {
+            return testGroupParametersAsync(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group, callback);
+        }
+    }
+
+    /**
+     * Fake endpoint to test group parameters (optional)
+     * Fake endpoint to test group parameters (optional)
+     * @param requiredStringGroup Required String in group parameters (required)
+     * @param requiredBooleanGroup Required Boolean in group parameters (required)
+     * @param requiredInt64Group Required Integer in group parameters (required)
+     * @return APItestGroupParametersRequest
+     */
+    public APItestGroupParametersRequest testGroupParameters(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group) {
+        return new APItestGroupParametersRequest(requiredStringGroup, requiredBooleanGroup, requiredInt64Group);
+    }
     /**
      * Build call for testInlineAdditionalProperties
      * @param requestBody request body (required)

samples/client/petstore/java/okhttp-gson-parcelableModel/src/test/java/org/openapitools/client/api/FakeApiTest.java

@@ -220,7 +220,11 @@ public class FakeApiTest {
         Integer stringGroup = null;
         Boolean booleanGroup = null;
         Long int64Group = null;
-        api.testGroupParameters(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group);
+        api.testGroupParameters(requiredStringGroup, requiredBooleanGroup, requiredInt64Group)
+                .stringGroup(stringGroup)
+                .booleanGroup(booleanGroup)
+                .int64Group(int64Group)
+                .execute();
 
         // TODO: test validations
     }

samples/client/petstore/java/okhttp-gson/docs/FakeApi.md

@@ -470,7 +470,7 @@ No authorization required
 
 <a name="testGroupParameters"></a>
 # **testGroupParameters**
-> testGroupParameters(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group)
+> testGroupParameters(requiredStringGroup, requiredBooleanGroup, requiredInt64Group).stringGroup(stringGroup).booleanGroup(booleanGroup).int64Group(int64Group).execute();
 
 Fake endpoint to test group parameters (optional)
 
@@ -491,7 +491,11 @@ Integer stringGroup = 56; // Integer | String in group parameters
 Boolean booleanGroup = true; // Boolean | Boolean in group parameters
 Long int64Group = 56L; // Long | Integer in group parameters
 try {
-    apiInstance.testGroupParameters(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group);
+    apiInstance.testGroupParameters(requiredStringGroup, requiredBooleanGroup, requiredInt64Group)
+            .stringGroup(stringGroup)
+            .booleanGroup(booleanGroup)
+            .int64Group(int64Group)
+            .execute();
 } catch (ApiException e) {
     System.err.println("Exception when calling FakeApi#testGroupParameters");
     e.printStackTrace();

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/api/FakeApi.java

@@ -1305,20 +1305,7 @@ public class FakeApi {
         apiClient.executeAsync(call, callback);
         return call;
     }
-    /**
+    private com.squareup.okhttp.Call testGroupParametersCall(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
-     * Build call for testGroupParameters
-     * @param requiredStringGroup Required String in group parameters (required)
-     * @param requiredBooleanGroup Required Boolean in group parameters (required)
-     * @param requiredInt64Group Required Integer in group parameters (required)
-     * @param stringGroup String in group parameters (optional)
-     * @param booleanGroup Boolean in group parameters (optional)
-     * @param int64Group Integer in group parameters (optional)
-     * @param progressListener Progress listener
-     * @param progressRequestListener Progress request listener
-     * @return Call to execute
-     * @throws ApiException If fail to serialize the request body object
-     */
-    public com.squareup.okhttp.Call testGroupParametersCall(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
         Object localVarPostBody = new Object();
 
         // create path and map variables
@@ -1406,52 +1393,13 @@ public class FakeApi {
 
     }
 
-    /**
-     * Fake endpoint to test group parameters (optional)
-     * Fake endpoint to test group parameters (optional)
-     * @param requiredStringGroup Required String in group parameters (required)
-     * @param requiredBooleanGroup Required Boolean in group parameters (required)
-     * @param requiredInt64Group Required Integer in group parameters (required)
-     * @param stringGroup String in group parameters (optional)
-     * @param booleanGroup Boolean in group parameters (optional)
-     * @param int64Group Integer in group parameters (optional)
-     * @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body
-     */
-    public void testGroupParameters(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group) throws ApiException {
-        testGroupParametersWithHttpInfo(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group);
-    }
 
-    /**
+    private ApiResponse<Void> testGroupParametersWithHttpInfo(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group) throws ApiException {
-     * Fake endpoint to test group parameters (optional)
-     * Fake endpoint to test group parameters (optional)
-     * @param requiredStringGroup Required String in group parameters (required)
-     * @param requiredBooleanGroup Required Boolean in group parameters (required)
-     * @param requiredInt64Group Required Integer in group parameters (required)
-     * @param stringGroup String in group parameters (optional)
-     * @param booleanGroup Boolean in group parameters (optional)
-     * @param int64Group Integer in group parameters (optional)
-     * @return ApiResponse&lt;Void&gt;
-     * @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body
-     */
-    public ApiResponse<Void> testGroupParametersWithHttpInfo(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group) throws ApiException {
         com.squareup.okhttp.Call call = testGroupParametersValidateBeforeCall(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group, null, null);
         return apiClient.execute(call);
     }
 
-    /**
+    private com.squareup.okhttp.Call testGroupParametersAsync(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group, final ApiCallback<Void> callback) throws ApiException {
-     * Fake endpoint to test group parameters (optional) (asynchronously)
-     * Fake endpoint to test group parameters (optional)
-     * @param requiredStringGroup Required String in group parameters (required)
-     * @param requiredBooleanGroup Required Boolean in group parameters (required)
-     * @param requiredInt64Group Required Integer in group parameters (required)
-     * @param stringGroup String in group parameters (optional)
-     * @param booleanGroup Boolean in group parameters (optional)
-     * @param int64Group Integer in group parameters (optional)
-     * @param callback The callback to be executed when the API call finishes
-     * @return The request call
-     * @throws ApiException If fail to process the API call, e.g. serializing the request body object
-     */
-    public com.squareup.okhttp.Call testGroupParametersAsync(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group, final ApiCallback<Void> callback) throws ApiException {
 
         ProgressResponseBody.ProgressListener progressListener = null;
         ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
@@ -1476,6 +1424,101 @@ public class FakeApi {
         apiClient.executeAsync(call, callback);
         return call;
     }
+
+    public class APItestGroupParametersRequest {
+        private final Integer requiredStringGroup;
+        private final Boolean requiredBooleanGroup;
+        private final Long requiredInt64Group;
+        private Integer stringGroup;
+        private Boolean booleanGroup;
+        private Long int64Group;
+
+        private APItestGroupParametersRequest(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group) {
+            this.requiredStringGroup = requiredStringGroup;
+            this.requiredBooleanGroup = requiredBooleanGroup;
+            this.requiredInt64Group = requiredInt64Group;
+        }
+
+        /**
+         * Set stringGroup
+         * @param stringGroup String in group parameters (optional)
+         * @return APItestGroupParametersRequest
+         */
+        public APItestGroupParametersRequest stringGroup(Integer stringGroup) {
+            this.stringGroup = stringGroup;
+            return this;
+        }
+
+        /**
+         * Set booleanGroup
+         * @param booleanGroup Boolean in group parameters (optional)
+         * @return APItestGroupParametersRequest
+         */
+        public APItestGroupParametersRequest booleanGroup(Boolean booleanGroup) {
+            this.booleanGroup = booleanGroup;
+            return this;
+        }
+
+        /**
+         * Set int64Group
+         * @param int64Group Integer in group parameters (optional)
+         * @return APItestGroupParametersRequest
+         */
+        public APItestGroupParametersRequest int64Group(Long int64Group) {
+            this.int64Group = int64Group;
+            return this;
+        }
+
+        /**
+         * Build call for testGroupParameters
+         * @param progressListener Progress listener
+         * @param progressRequestListener Progress request listener
+         * @return Call to execute
+         * @throws ApiException If fail to serialize the request body object
+         */
+        public com.squareup.okhttp.Call buildCall(final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
+            return testGroupParametersCall(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group, progressListener, progressRequestListener);
+        }
+
+        /**
+         * Execute testGroupParameters request
+         * @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body
+         */
+        public void execute() throws ApiException {
+            testGroupParametersWithHttpInfo(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group);
+        }
+
+        /**
+         * Execute testGroupParameters request with HTTP info returned
+         * @return ApiResponse&lt;Void&gt;
+         * @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body
+         */
+        public ApiResponse<Void> executeWithHttpInfo() throws ApiException {
+            return testGroupParametersWithHttpInfo(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group);
+        }
+
+        /**
+         * Execute testGroupParameters request (asynchronously)
+         * @param callback The callback to be executed when the API call finishes
+         * @return The request call
+         * @throws ApiException If fail to process the API call, e.g. serializing the request body object
+         */
+        public com.squareup.okhttp.Call executeAsync(final ApiCallback<Void> callback) throws ApiException {
+            return testGroupParametersAsync(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group, callback);
+        }
+    }
+
+    /**
+     * Fake endpoint to test group parameters (optional)
+     * Fake endpoint to test group parameters (optional)
+     * @param requiredStringGroup Required String in group parameters (required)
+     * @param requiredBooleanGroup Required Boolean in group parameters (required)
+     * @param requiredInt64Group Required Integer in group parameters (required)
+     * @return APItestGroupParametersRequest
+     */
+    public APItestGroupParametersRequest testGroupParameters(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group) {
+        return new APItestGroupParametersRequest(requiredStringGroup, requiredBooleanGroup, requiredInt64Group);
+    }
     /**
      * Build call for testInlineAdditionalProperties
      * @param requestBody request body (required)

samples/client/petstore/java/okhttp-gson/src/test/java/org/openapitools/client/api/FakeApiTest.java

@@ -220,7 +220,11 @@ public class FakeApiTest {
         Integer stringGroup = null;
         Boolean booleanGroup = null;
         Long int64Group = null;
-        api.testGroupParameters(requiredStringGroup, requiredBooleanGroup, requiredInt64Group, stringGroup, booleanGroup, int64Group);
+        api.testGroupParameters(requiredStringGroup, requiredBooleanGroup, requiredInt64Group)
+                .stringGroup(stringGroup)
+                .booleanGroup(booleanGroup)
+                .int64Group(int64Group)
+                .execute();
 
         // TODO: test validations
     }