Better tests for php-nextgen (#16569)

* better tests for php nextgen

* add new files

bin/configs/php-nextgen-echo-api.yaml

@@ -0,0 +1,6 @@
+generatorName: php-nextgen
+outputDir: samples/client/echo_api/php-nextgen
+inputSpec: modules/openapi-generator/src/test/resources/3_0/echo_api.yaml
+templateDir: modules/openapi-generator/src/main/resources/php-nextgen
+additionalProperties:
+  hideGenerationTimestamp: "true"

bin/configs/php-nextgen.yaml

@@ -1,4 +1,4 @@
 generatorName: php-nextgen
 outputDir: samples/client/petstore/php-nextgen/OpenAPIClient-php
-inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml
+inputSpec: modules/openapi-generator/src/test/resources/3_0/php-nextgen/petstore-with-fake-endpoints-models-for-testing.yaml
 templateDir: modules/openapi-generator/src/main/resources/php-nextgen

samples/client/echo_api/php-nextgen/.gitignore

@@ -0,0 +1,19 @@
+# ref: https://github.com/github/gitignore/blob/master/Composer.gitignore
+
+composer.phar
+/vendor/
+
+# Commit your application's lock file https://getcomposer.org/doc/01-basic-usage.md#commit-your-composer-lock-file-to-version-control
+# You may choose to ignore a library lock file http://getcomposer.org/doc/02-libraries.md#lock-file
+# makes sense since it's a library(client SDK) and not a project
+composer.lock
+
+# php-cs-fixer cache
+.php_cs.cache
+.php-cs-fixer.cache
+
+# PHPUnit cache
+.phpunit.result.cache
+
+# PHPLint cache
+build/phplint.cache

samples/client/echo_api/php-nextgen/.openapi-generator-ignore

@@ -0,0 +1,23 @@
+# OpenAPI Generator Ignore
+# Generated by openapi-generator https://github.com/openapitools/openapi-generator
+
+# Use this file to prevent files from being overwritten by the generator.
+# The patterns follow closely to .gitignore or .dockerignore.
+
+# As an example, the C# client generator defines ApiClient.cs.
+# You can make changes and tell OpenAPI Generator to ignore just this file by uncommenting the following line:
+#ApiClient.cs
+
+# You can match any string of characters against a directory, file or extension with a single asterisk (*):
+#foo/*/qux
+# The above matches foo/bar/qux and foo/baz/qux, but not foo/bar/baz/qux
+
+# You can recursively match patterns against a directory, file or extension with a double asterisk (**):
+#foo/**/qux
+# This matches foo/bar/qux, foo/baz/qux, and foo/bar/baz/qux
+
+# You can also negate patterns with an exclamation (!).
+# For example, you can ignore all files in a docs folder with the file extension .md:
+#docs/*.md
+# Then explicitly reverse the ignore rule for a single file:
+#!docs/README.md

samples/client/echo_api/php-nextgen/.openapi-generator/FILES

@@ -0,0 +1,47 @@
+.gitignore
+.php-cs-fixer.dist.php
+.phplint.yml
+.travis.yml
+README.md
+composer.json
+docs/Api/AuthApi.md
+docs/Api/BodyApi.md
+docs/Api/FormApi.md
+docs/Api/HeaderApi.md
+docs/Api/PathApi.md
+docs/Api/QueryApi.md
+docs/Model/Bird.md
+docs/Model/Category.md
+docs/Model/DataQuery.md
+docs/Model/DefaultValue.md
+docs/Model/NumberPropertiesOnly.md
+docs/Model/Pet.md
+docs/Model/Query.md
+docs/Model/StringEnumRef.md
+docs/Model/Tag.md
+docs/Model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.md
+docs/Model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.md
+git_push.sh
+phpunit.xml.dist
+src/Api/AuthApi.php
+src/Api/BodyApi.php
+src/Api/FormApi.php
+src/Api/HeaderApi.php
+src/Api/PathApi.php
+src/Api/QueryApi.php
+src/ApiException.php
+src/Configuration.php
+src/HeaderSelector.php
+src/Model/Bird.php
+src/Model/Category.php
+src/Model/DataQuery.php
+src/Model/DefaultValue.php
+src/Model/ModelInterface.php
+src/Model/NumberPropertiesOnly.php
+src/Model/Pet.php
+src/Model/Query.php
+src/Model/StringEnumRef.php
+src/Model/Tag.php
+src/Model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.php
+src/Model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.php
+src/ObjectSerializer.php

samples/client/echo_api/php-nextgen/.openapi-generator/VERSION

@@ -0,0 +1 @@
+7.0.1-SNAPSHOT

samples/client/echo_api/php-nextgen/.php-cs-fixer.dist.php

@@ -0,0 +1,29 @@
+<?php
+
+/**
+ * @generated
+ * @link https://github.com/FriendsOfPHP/PHP-CS-Fixer/blob/HEAD/doc/config.rst
+ */
+$finder = PhpCsFixer\Finder::create()
+    ->in(__DIR__)
+    ->exclude('vendor')
+    ->exclude('test')
+    ->exclude('tests')
+;
+
+$config = new PhpCsFixer\Config();
+return $config->setRules([
+        '@PSR12' => true,
+        'phpdoc_order' => true,
+        'array_syntax' => [ 'syntax' => 'short' ],
+        'strict_comparison' => true,
+        'strict_param' => true,
+        'no_trailing_whitespace' => false,
+        'no_trailing_whitespace_in_comment' => false,
+        'braces' => false,
+        'single_blank_line_at_eof' => false,
+        'blank_line_after_namespace' => false,
+        'no_leading_import_slash' => false,
+    ])
+    ->setFinder($finder)
+;

samples/client/echo_api/php-nextgen/.phplint.yml

@@ -0,0 +1,11 @@
+path:
+  - ./src
+  - ./tests
+jobs: 10
+extensions:
+  - php
+exclude:
+  - vendor
+warning: true
+memory-limit: -1
+no-cache: true

samples/client/echo_api/php-nextgen/.travis.yml

@@ -0,0 +1,12 @@
+language: php
+# Jammy Jellyfish environment has preinstalled PHP 8.1
+# Focal Fossa doesn't fit since it contains preinstalled PHP 7.4 only
+# https://docs.travis-ci.com/user/reference/jammy/#php-support
+dist: jammy
+os:
+  - linux
+php:
+  - 8.1
+  - 8.2
+before_install: "composer install"
+script: "vendor/bin/phpunit"

samples/client/echo_api/php-nextgen/README.md

@@ -0,0 +1,138 @@
+# OpenAPIClient-php
+
+Echo Server API
+
+
+## Installation & Usage
+
+### Requirements
+
+PHP 8.1 and later.
+
+### Composer
+
+To install the bindings via [Composer](https://getcomposer.org/), add the following to `composer.json`:
+
+```json
+{
+  "repositories": [
+    {
+      "type": "vcs",
+      "url": "https://github.com/GIT_USER_ID/GIT_REPO_ID.git"
+    }
+  ],
+  "require": {
+    "GIT_USER_ID/GIT_REPO_ID": "*@dev"
+  }
+}
+```
+
+Then run `composer install`
+
+### Manual Installation
+
+Download the files and include `autoload.php`:
+
+```php
+<?php
+require_once('/path/to/OpenAPIClient-php/vendor/autoload.php');
+```
+
+## Getting Started
+
+Please follow the [installation procedure](#installation--usage) and then run the following:
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+// Configure HTTP basic authorization: http_auth
+$config = OpenAPI\Client\Configuration::getDefaultConfiguration()
+              ->setUsername('YOUR_USERNAME')
+              ->setPassword('YOUR_PASSWORD');
+
+
+$apiInstance = new OpenAPI\Client\Api\AuthApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client(),
+    $config
+);
+
+try {
+    $result = $apiInstance->testAuthHttpBasic();
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling AuthApi->testAuthHttpBasic: ', $e->getMessage(), PHP_EOL;
+}
+
+```
+
+## API Endpoints
+
+All URIs are relative to *http://localhost:3000*
+
+Class | Method | HTTP request | Description
+------------ | ------------- | ------------- | -------------
+*AuthApi* | [**testAuthHttpBasic**](docs/Api/AuthApi.md#testauthhttpbasic) | **POST** /auth/http/basic | To test HTTP basic authentication
+*BodyApi* | [**testBinaryGif**](docs/Api/BodyApi.md#testbinarygif) | **POST** /binary/gif | Test binary (gif) response body
+*BodyApi* | [**testBodyApplicationOctetstreamBinary**](docs/Api/BodyApi.md#testbodyapplicationoctetstreambinary) | **POST** /body/application/octetstream/binary | Test body parameter(s)
+*BodyApi* | [**testBodyMultipartFormdataArrayOfBinary**](docs/Api/BodyApi.md#testbodymultipartformdataarrayofbinary) | **POST** /body/application/octetstream/array_of_binary | Test array of binary in multipart mime
+*BodyApi* | [**testEchoBodyFreeFormObjectResponseString**](docs/Api/BodyApi.md#testechobodyfreeformobjectresponsestring) | **POST** /echo/body/FreeFormObject/response_string | Test free form object
+*BodyApi* | [**testEchoBodyPet**](docs/Api/BodyApi.md#testechobodypet) | **POST** /echo/body/Pet | Test body parameter(s)
+*BodyApi* | [**testEchoBodyPetResponseString**](docs/Api/BodyApi.md#testechobodypetresponsestring) | **POST** /echo/body/Pet/response_string | Test empty response body
+*BodyApi* | [**testEchoBodyTagResponseString**](docs/Api/BodyApi.md#testechobodytagresponsestring) | **POST** /echo/body/Tag/response_string | Test empty json (request body)
+*FormApi* | [**testFormIntegerBooleanString**](docs/Api/FormApi.md#testformintegerbooleanstring) | **POST** /form/integer/boolean/string | Test form parameter(s)
+*FormApi* | [**testFormOneof**](docs/Api/FormApi.md#testformoneof) | **POST** /form/oneof | Test form parameter(s) for oneOf schema
+*HeaderApi* | [**testHeaderIntegerBooleanString**](docs/Api/HeaderApi.md#testheaderintegerbooleanstring) | **GET** /header/integer/boolean/string | Test header parameter(s)
+*PathApi* | [**testsPathStringPathStringIntegerPathInteger**](docs/Api/PathApi.md#testspathstringpathstringintegerpathinteger) | **GET** /path/string/{path_string}/integer/{path_integer} | Test path parameter(s)
+*QueryApi* | [**testEnumRefString**](docs/Api/QueryApi.md#testenumrefstring) | **GET** /query/enum_ref_string | Test query parameter(s)
+*QueryApi* | [**testQueryDatetimeDateString**](docs/Api/QueryApi.md#testquerydatetimedatestring) | **GET** /query/datetime/date/string | Test query parameter(s)
+*QueryApi* | [**testQueryIntegerBooleanString**](docs/Api/QueryApi.md#testqueryintegerbooleanstring) | **GET** /query/integer/boolean/string | Test query parameter(s)
+*QueryApi* | [**testQueryStyleDeepObjectExplodeTrueObject**](docs/Api/QueryApi.md#testquerystyledeepobjectexplodetrueobject) | **GET** /query/style_deepObject/explode_true/object | Test query parameter(s)
+*QueryApi* | [**testQueryStyleDeepObjectExplodeTrueObjectAllOf**](docs/Api/QueryApi.md#testquerystyledeepobjectexplodetrueobjectallof) | **GET** /query/style_deepObject/explode_true/object/allOf | Test query parameter(s)
+*QueryApi* | [**testQueryStyleFormExplodeTrueArrayString**](docs/Api/QueryApi.md#testquerystyleformexplodetruearraystring) | **GET** /query/style_form/explode_true/array_string | Test query parameter(s)
+*QueryApi* | [**testQueryStyleFormExplodeTrueObject**](docs/Api/QueryApi.md#testquerystyleformexplodetrueobject) | **GET** /query/style_form/explode_true/object | Test query parameter(s)
+*QueryApi* | [**testQueryStyleFormExplodeTrueObjectAllOf**](docs/Api/QueryApi.md#testquerystyleformexplodetrueobjectallof) | **GET** /query/style_form/explode_true/object/allOf | Test query parameter(s)
+
+## Models
+
+- [Bird](docs/Model/Bird.md)
+- [Category](docs/Model/Category.md)
+- [DataQuery](docs/Model/DataQuery.md)
+- [DefaultValue](docs/Model/DefaultValue.md)
+- [NumberPropertiesOnly](docs/Model/NumberPropertiesOnly.md)
+- [Pet](docs/Model/Pet.md)
+- [Query](docs/Model/Query.md)
+- [StringEnumRef](docs/Model/StringEnumRef.md)
+- [Tag](docs/Model/Tag.md)
+- [TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter](docs/Model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.md)
+- [TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter](docs/Model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.md)
+
+## Authorization
+
+### http_auth
+
+- **Type**: HTTP basic authentication
+
+## Tests
+
+To run the tests, use:
+
+```bash
+composer install
+vendor/bin/phpunit
+```
+
+## Author
+
+team@openapitools.org
+
+## About this package
+
+This PHP package is automatically generated by the [OpenAPI Generator](https://openapi-generator.tech) project:
+
+- API version: `0.1.0`
+- Build package: `org.openapitools.codegen.languages.PhpNextgenClientCodegen`

samples/client/echo_api/php-nextgen/composer.json

@@ -0,0 +1,45 @@
+{
+    "description": "Echo Server API",
+    "keywords": [
+        "openapitools",
+        "openapi-generator",
+        "openapi",
+        "php",
+        "sdk",
+        "rest",
+        "api"
+    ],
+    "homepage": "https://openapi-generator.tech",
+    "license": "unlicense",
+    "authors": [
+        {
+            "name": "OpenAPI-Generator contributors",
+            "homepage": "https://openapi-generator.tech"
+        }
+    ],
+    "require": {
+        "php": "^8.1",
+        "ext-curl": "*",
+        "ext-json": "*",
+        "ext-mbstring": "*",
+        "guzzlehttp/guzzle": "^7.4.5",
+        "guzzlehttp/psr7": "^2.0"
+    },
+    "require-dev": {
+        "friendsofphp/php-cs-fixer": "^3.5",
+        "overtrue/phplint": "^9.0",
+        "phpunit/phpunit": "^9.0"
+    },
+    "autoload": {
+        "psr-4": { "OpenAPI\\Client\\" : "src/" }
+    },
+    "autoload-dev": {
+        "psr-4": { "OpenAPI\\Client\\Test\\" : "tests/" }
+    },
+    "scripts": {
+        "test": [
+            "@phplint"
+        ],
+        "phplint": "phplint"
+    }
+}

samples/client/echo_api/php-nextgen/docs/Api/AuthApi.md

@@ -0,0 +1,67 @@
+# OpenAPI\Client\AuthApi
+
+All URIs are relative to http://localhost:3000, except if the operation defines another base path.
+
+| Method | HTTP request | Description |
+| ------------- | ------------- | ------------- |
+| [**testAuthHttpBasic()**](AuthApi.md#testAuthHttpBasic) | **POST** /auth/http/basic | To test HTTP basic authentication |
+
+
+## `testAuthHttpBasic()`
+
+```php
+testAuthHttpBasic(): string
+```
+
+To test HTTP basic authentication
+
+To test HTTP basic authentication
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+// Configure HTTP basic authorization: http_auth
+$config = OpenAPI\Client\Configuration::getDefaultConfiguration()
+              ->setUsername('YOUR_USERNAME')
+              ->setPassword('YOUR_PASSWORD');
+
+
+$apiInstance = new OpenAPI\Client\Api\AuthApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client(),
+    $config
+);
+
+try {
+    $result = $apiInstance->testAuthHttpBasic();
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling AuthApi->testAuthHttpBasic: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+This endpoint does not need any parameter.
+
+### Return type
+
+**string**
+
+### Authorization
+
+[http_auth](../../README.md#http_auth)
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/docs/Api/BodyApi.md

@@ -0,0 +1,403 @@
+# OpenAPI\Client\BodyApi
+
+All URIs are relative to http://localhost:3000, except if the operation defines another base path.
+
+| Method | HTTP request | Description |
+| ------------- | ------------- | ------------- |
+| [**testBinaryGif()**](BodyApi.md#testBinaryGif) | **POST** /binary/gif | Test binary (gif) response body |
+| [**testBodyApplicationOctetstreamBinary()**](BodyApi.md#testBodyApplicationOctetstreamBinary) | **POST** /body/application/octetstream/binary | Test body parameter(s) |
+| [**testBodyMultipartFormdataArrayOfBinary()**](BodyApi.md#testBodyMultipartFormdataArrayOfBinary) | **POST** /body/application/octetstream/array_of_binary | Test array of binary in multipart mime |
+| [**testEchoBodyFreeFormObjectResponseString()**](BodyApi.md#testEchoBodyFreeFormObjectResponseString) | **POST** /echo/body/FreeFormObject/response_string | Test free form object |
+| [**testEchoBodyPet()**](BodyApi.md#testEchoBodyPet) | **POST** /echo/body/Pet | Test body parameter(s) |
+| [**testEchoBodyPetResponseString()**](BodyApi.md#testEchoBodyPetResponseString) | **POST** /echo/body/Pet/response_string | Test empty response body |
+| [**testEchoBodyTagResponseString()**](BodyApi.md#testEchoBodyTagResponseString) | **POST** /echo/body/Tag/response_string | Test empty json (request body) |
+
+
+## `testBinaryGif()`
+
+```php
+testBinaryGif(): \SplFileObject
+```
+
+Test binary (gif) response body
+
+Test binary (gif) response body
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\BodyApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+
+try {
+    $result = $apiInstance->testBinaryGif();
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling BodyApi->testBinaryGif: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+This endpoint does not need any parameter.
+
+### Return type
+
+**\SplFileObject**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: `image/gif`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)
+
+## `testBodyApplicationOctetstreamBinary()`
+
+```php
+testBodyApplicationOctetstreamBinary($body): string
+```
+
+Test body parameter(s)
+
+Test body parameter(s)
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\BodyApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$body = "/path/to/file.txt"; // \SplFileObject
+
+try {
+    $result = $apiInstance->testBodyApplicationOctetstreamBinary($body);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling BodyApi->testBodyApplicationOctetstreamBinary: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **body** | **\SplFileObject****\SplFileObject**|  | [optional] |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: `application/octet-stream`
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)
+
+## `testBodyMultipartFormdataArrayOfBinary()`
+
+```php
+testBodyMultipartFormdataArrayOfBinary($files): string
+```
+
+Test array of binary in multipart mime
+
+Test array of binary in multipart mime
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\BodyApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$files = array("/path/to/file.txt"); // \SplFileObject[]
+
+try {
+    $result = $apiInstance->testBodyMultipartFormdataArrayOfBinary($files);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling BodyApi->testBodyMultipartFormdataArrayOfBinary: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **files** | **\SplFileObject[]**|  | |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: `multipart/form-data`
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)
+
+## `testEchoBodyFreeFormObjectResponseString()`
+
+```php
+testEchoBodyFreeFormObjectResponseString($body): string
+```
+
+Test free form object
+
+Test free form object
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\BodyApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$body = array('key' => new \stdClass); // object | Free form object
+
+try {
+    $result = $apiInstance->testEchoBodyFreeFormObjectResponseString($body);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling BodyApi->testEchoBodyFreeFormObjectResponseString: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **body** | **object**| Free form object | [optional] |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: `application/json`
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)
+
+## `testEchoBodyPet()`
+
+```php
+testEchoBodyPet($pet): \OpenAPI\Client\Model\Pet
+```
+
+Test body parameter(s)
+
+Test body parameter(s)
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\BodyApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$pet = new \OpenAPI\Client\Model\Pet(); // \OpenAPI\Client\Model\Pet | Pet object that needs to be added to the store
+
+try {
+    $result = $apiInstance->testEchoBodyPet($pet);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling BodyApi->testEchoBodyPet: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **pet** | [**\OpenAPI\Client\Model\Pet**](../Model/Pet.md)| Pet object that needs to be added to the store | [optional] |
+
+### Return type
+
+[**\OpenAPI\Client\Model\Pet**](../Model/Pet.md)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: `application/json`
+- **Accept**: `application/json`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)
+
+## `testEchoBodyPetResponseString()`
+
+```php
+testEchoBodyPetResponseString($pet): string
+```
+
+Test empty response body
+
+Test empty response body
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\BodyApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$pet = new \OpenAPI\Client\Model\Pet(); // \OpenAPI\Client\Model\Pet | Pet object that needs to be added to the store
+
+try {
+    $result = $apiInstance->testEchoBodyPetResponseString($pet);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling BodyApi->testEchoBodyPetResponseString: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **pet** | [**\OpenAPI\Client\Model\Pet**](../Model/Pet.md)| Pet object that needs to be added to the store | [optional] |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: `application/json`
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)
+
+## `testEchoBodyTagResponseString()`
+
+```php
+testEchoBodyTagResponseString($tag): string
+```
+
+Test empty json (request body)
+
+Test empty json (request body)
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\BodyApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$tag = new \OpenAPI\Client\Model\Tag(); // \OpenAPI\Client\Model\Tag | Tag object
+
+try {
+    $result = $apiInstance->testEchoBodyTagResponseString($tag);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling BodyApi->testEchoBodyTagResponseString: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **tag** | [**\OpenAPI\Client\Model\Tag**](../Model/Tag.md)| Tag object | [optional] |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: `application/json`
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/docs/Api/FormApi.md

@@ -0,0 +1,135 @@
+# OpenAPI\Client\FormApi
+
+All URIs are relative to http://localhost:3000, except if the operation defines another base path.
+
+| Method | HTTP request | Description |
+| ------------- | ------------- | ------------- |
+| [**testFormIntegerBooleanString()**](FormApi.md#testFormIntegerBooleanString) | **POST** /form/integer/boolean/string | Test form parameter(s) |
+| [**testFormOneof()**](FormApi.md#testFormOneof) | **POST** /form/oneof | Test form parameter(s) for oneOf schema |
+
+
+## `testFormIntegerBooleanString()`
+
+```php
+testFormIntegerBooleanString($integer_form, $boolean_form, $string_form): string
+```
+
+Test form parameter(s)
+
+Test form parameter(s)
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\FormApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$integer_form = 56; // int
+$boolean_form = True; // bool
+$string_form = 'string_form_example'; // string
+
+try {
+    $result = $apiInstance->testFormIntegerBooleanString($integer_form, $boolean_form, $string_form);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling FormApi->testFormIntegerBooleanString: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **integer_form** | **int**|  | [optional] |
+| **boolean_form** | **bool**|  | [optional] |
+| **string_form** | **string**|  | [optional] |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: `application/x-www-form-urlencoded`
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)
+
+## `testFormOneof()`
+
+```php
+testFormOneof($form1, $form2, $form3, $form4, $id, $name): string
+```
+
+Test form parameter(s) for oneOf schema
+
+Test form parameter(s) for oneOf schema
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\FormApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$form1 = 'form1_example'; // string
+$form2 = 56; // int
+$form3 = 'form3_example'; // string
+$form4 = True; // bool
+$id = 56; // int
+$name = 'name_example'; // string
+
+try {
+    $result = $apiInstance->testFormOneof($form1, $form2, $form3, $form4, $id, $name);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling FormApi->testFormOneof: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **form1** | **string**|  | [optional] |
+| **form2** | **int**|  | [optional] |
+| **form3** | **string**|  | [optional] |
+| **form4** | **bool**|  | [optional] |
+| **id** | **int**|  | [optional] |
+| **name** | **string**|  | [optional] |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: `application/x-www-form-urlencoded`
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/docs/Api/HeaderApi.md

@@ -0,0 +1,68 @@
+# OpenAPI\Client\HeaderApi
+
+All URIs are relative to http://localhost:3000, except if the operation defines another base path.
+
+| Method | HTTP request | Description |
+| ------------- | ------------- | ------------- |
+| [**testHeaderIntegerBooleanString()**](HeaderApi.md#testHeaderIntegerBooleanString) | **GET** /header/integer/boolean/string | Test header parameter(s) |
+
+
+## `testHeaderIntegerBooleanString()`
+
+```php
+testHeaderIntegerBooleanString($integer_header, $boolean_header, $string_header): string
+```
+
+Test header parameter(s)
+
+Test header parameter(s)
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\HeaderApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$integer_header = 56; // int
+$boolean_header = True; // bool
+$string_header = 'string_header_example'; // string
+
+try {
+    $result = $apiInstance->testHeaderIntegerBooleanString($integer_header, $boolean_header, $string_header);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling HeaderApi->testHeaderIntegerBooleanString: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **integer_header** | **int**|  | [optional] |
+| **boolean_header** | **bool**|  | [optional] |
+| **string_header** | **string**|  | [optional] |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/docs/Api/PathApi.md

@@ -0,0 +1,66 @@
+# OpenAPI\Client\PathApi
+
+All URIs are relative to http://localhost:3000, except if the operation defines another base path.
+
+| Method | HTTP request | Description |
+| ------------- | ------------- | ------------- |
+| [**testsPathStringPathStringIntegerPathInteger()**](PathApi.md#testsPathStringPathStringIntegerPathInteger) | **GET** /path/string/{path_string}/integer/{path_integer} | Test path parameter(s) |
+
+
+## `testsPathStringPathStringIntegerPathInteger()`
+
+```php
+testsPathStringPathStringIntegerPathInteger($path_string, $path_integer): string
+```
+
+Test path parameter(s)
+
+Test path parameter(s)
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\PathApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$path_string = 'path_string_example'; // string
+$path_integer = 56; // int
+
+try {
+    $result = $apiInstance->testsPathStringPathStringIntegerPathInteger($path_string, $path_integer);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling PathApi->testsPathStringPathStringIntegerPathInteger: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **path_string** | **string**|  | |
+| **path_integer** | **int**|  | |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/docs/Api/QueryApi.md

@@ -0,0 +1,471 @@
+# OpenAPI\Client\QueryApi
+
+All URIs are relative to http://localhost:3000, except if the operation defines another base path.
+
+| Method | HTTP request | Description |
+| ------------- | ------------- | ------------- |
+| [**testEnumRefString()**](QueryApi.md#testEnumRefString) | **GET** /query/enum_ref_string | Test query parameter(s) |
+| [**testQueryDatetimeDateString()**](QueryApi.md#testQueryDatetimeDateString) | **GET** /query/datetime/date/string | Test query parameter(s) |
+| [**testQueryIntegerBooleanString()**](QueryApi.md#testQueryIntegerBooleanString) | **GET** /query/integer/boolean/string | Test query parameter(s) |
+| [**testQueryStyleDeepObjectExplodeTrueObject()**](QueryApi.md#testQueryStyleDeepObjectExplodeTrueObject) | **GET** /query/style_deepObject/explode_true/object | Test query parameter(s) |
+| [**testQueryStyleDeepObjectExplodeTrueObjectAllOf()**](QueryApi.md#testQueryStyleDeepObjectExplodeTrueObjectAllOf) | **GET** /query/style_deepObject/explode_true/object/allOf | Test query parameter(s) |
+| [**testQueryStyleFormExplodeTrueArrayString()**](QueryApi.md#testQueryStyleFormExplodeTrueArrayString) | **GET** /query/style_form/explode_true/array_string | Test query parameter(s) |
+| [**testQueryStyleFormExplodeTrueObject()**](QueryApi.md#testQueryStyleFormExplodeTrueObject) | **GET** /query/style_form/explode_true/object | Test query parameter(s) |
+| [**testQueryStyleFormExplodeTrueObjectAllOf()**](QueryApi.md#testQueryStyleFormExplodeTrueObjectAllOf) | **GET** /query/style_form/explode_true/object/allOf | Test query parameter(s) |
+
+
+## `testEnumRefString()`
+
+```php
+testEnumRefString($enum_ref_string_query): string
+```
+
+Test query parameter(s)
+
+Test query parameter(s)
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\QueryApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$enum_ref_string_query = new \OpenAPI\Client\Model\StringEnumRef(); // StringEnumRef
+
+try {
+    $result = $apiInstance->testEnumRefString($enum_ref_string_query);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling QueryApi->testEnumRefString: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **enum_ref_string_query** | [**StringEnumRef**](../Model/.md)|  | [optional] |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)
+
+## `testQueryDatetimeDateString()`
+
+```php
+testQueryDatetimeDateString($datetime_query, $date_query, $string_query): string
+```
+
+Test query parameter(s)
+
+Test query parameter(s)
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\QueryApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$datetime_query = new \DateTime("2013-10-20T19:20:30+01:00"); // \DateTime
+$date_query = new \DateTime("2013-10-20T19:20:30+01:00"); // \DateTime
+$string_query = 'string_query_example'; // string
+
+try {
+    $result = $apiInstance->testQueryDatetimeDateString($datetime_query, $date_query, $string_query);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling QueryApi->testQueryDatetimeDateString: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **datetime_query** | **\DateTime**|  | [optional] |
+| **date_query** | **\DateTime**|  | [optional] |
+| **string_query** | **string**|  | [optional] |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)
+
+## `testQueryIntegerBooleanString()`
+
+```php
+testQueryIntegerBooleanString($integer_query, $boolean_query, $string_query): string
+```
+
+Test query parameter(s)
+
+Test query parameter(s)
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\QueryApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$integer_query = 56; // int
+$boolean_query = True; // bool
+$string_query = 'string_query_example'; // string
+
+try {
+    $result = $apiInstance->testQueryIntegerBooleanString($integer_query, $boolean_query, $string_query);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling QueryApi->testQueryIntegerBooleanString: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **integer_query** | **int**|  | [optional] |
+| **boolean_query** | **bool**|  | [optional] |
+| **string_query** | **string**|  | [optional] |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)
+
+## `testQueryStyleDeepObjectExplodeTrueObject()`
+
+```php
+testQueryStyleDeepObjectExplodeTrueObject($query_object): string
+```
+
+Test query parameter(s)
+
+Test query parameter(s)
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\QueryApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$query_object = new \OpenAPI\Client\Model\Pet(); // Pet
+
+try {
+    $result = $apiInstance->testQueryStyleDeepObjectExplodeTrueObject($query_object);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling QueryApi->testQueryStyleDeepObjectExplodeTrueObject: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **query_object** | [**Pet**](../Model/.md)|  | [optional] |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)
+
+## `testQueryStyleDeepObjectExplodeTrueObjectAllOf()`
+
+```php
+testQueryStyleDeepObjectExplodeTrueObjectAllOf($query_object): string
+```
+
+Test query parameter(s)
+
+Test query parameter(s)
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\QueryApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$query_object = new \OpenAPI\Client\Model\TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter(); // TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter
+
+try {
+    $result = $apiInstance->testQueryStyleDeepObjectExplodeTrueObjectAllOf($query_object);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling QueryApi->testQueryStyleDeepObjectExplodeTrueObjectAllOf: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **query_object** | [**TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter**](../Model/.md)|  | [optional] |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)
+
+## `testQueryStyleFormExplodeTrueArrayString()`
+
+```php
+testQueryStyleFormExplodeTrueArrayString($query_object): string
+```
+
+Test query parameter(s)
+
+Test query parameter(s)
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\QueryApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$query_object = new \OpenAPI\Client\Model\TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter(); // TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter
+
+try {
+    $result = $apiInstance->testQueryStyleFormExplodeTrueArrayString($query_object);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling QueryApi->testQueryStyleFormExplodeTrueArrayString: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **query_object** | [**TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter**](../Model/.md)|  | [optional] |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)
+
+## `testQueryStyleFormExplodeTrueObject()`
+
+```php
+testQueryStyleFormExplodeTrueObject($query_object): string
+```
+
+Test query parameter(s)
+
+Test query parameter(s)
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\QueryApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$query_object = new \OpenAPI\Client\Model\Pet(); // Pet
+
+try {
+    $result = $apiInstance->testQueryStyleFormExplodeTrueObject($query_object);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling QueryApi->testQueryStyleFormExplodeTrueObject: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **query_object** | [**Pet**](../Model/.md)|  | [optional] |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)
+
+## `testQueryStyleFormExplodeTrueObjectAllOf()`
+
+```php
+testQueryStyleFormExplodeTrueObjectAllOf($query_object): string
+```
+
+Test query parameter(s)
+
+Test query parameter(s)
+
+### Example
+
+```php
+<?php
+require_once(__DIR__ . '/vendor/autoload.php');
+
+
+
+$apiInstance = new OpenAPI\Client\Api\QueryApi(
+    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
+    // This is optional, `GuzzleHttp\Client` will be used as default.
+    new GuzzleHttp\Client()
+);
+$query_object = new \OpenAPI\Client\Model\DataQuery(); // DataQuery
+
+try {
+    $result = $apiInstance->testQueryStyleFormExplodeTrueObjectAllOf($query_object);
+    print_r($result);
+} catch (Exception $e) {
+    echo 'Exception when calling QueryApi->testQueryStyleFormExplodeTrueObjectAllOf: ', $e->getMessage(), PHP_EOL;
+}
+```
+
+### Parameters
+
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **query_object** | [**DataQuery**](../Model/.md)|  | [optional] |
+
+### Return type
+
+**string**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: `text/plain`
+
+[[Back to top]](#) [[Back to API list]](../../README.md#endpoints)
+[[Back to Model list]](../../README.md#models)
+[[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/docs/Model/Bird.md

@@ -0,0 +1,10 @@
+# # Bird
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**size** | **string** |  | [optional]
+**color** | **string** |  | [optional]
+
+[[Back to Model list]](../../README.md#models) [[Back to API list]](../../README.md#endpoints) [[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/docs/Model/Category.md

@@ -0,0 +1,10 @@
+# # Category
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**id** | **int** |  | [optional]
+**name** | **string** |  | [optional]
+
+[[Back to Model list]](../../README.md#models) [[Back to API list]](../../README.md#endpoints) [[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/docs/Model/DataQuery.md

@@ -0,0 +1,11 @@
+# # DataQuery
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**suffix** | **string** | test suffix | [optional]
+**text** | **string** | Some text containing white spaces | [optional]
+**date** | **\DateTime** | A date | [optional]
+
+[[Back to Model list]](../../README.md#models) [[Back to API list]](../../README.md#endpoints) [[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/docs/Model/DefaultValue.md

@@ -0,0 +1,16 @@
+# # DefaultValue
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**array_string_enum_ref_default** | [**\OpenAPI\Client\Model\StringEnumRef[]**](StringEnumRef.md) |  | [optional]
+**array_string_enum_default** | **string[]** |  | [optional]
+**array_string_default** | **string[]** |  | [optional]
+**array_integer_default** | **int[]** |  | [optional]
+**array_string** | **string[]** |  | [optional]
+**array_string_nullable** | **string[]** |  | [optional]
+**array_string_extension_nullable** | **string[]** |  | [optional]
+**string_nullable** | **string** |  | [optional]
+
+[[Back to Model list]](../../README.md#models) [[Back to API list]](../../README.md#endpoints) [[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/docs/Model/NumberPropertiesOnly.md

@@ -0,0 +1,11 @@
+# # NumberPropertiesOnly
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**number** | **float** |  | [optional]
+**float** | **float** |  | [optional]
+**double** | **float** |  | [optional]
+
+[[Back to Model list]](../../README.md#models) [[Back to API list]](../../README.md#endpoints) [[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/docs/Model/Pet.md

@@ -0,0 +1,14 @@
+# # Pet
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**id** | **int** |  | [optional]
+**name** | **string** |  |
+**category** | [**\OpenAPI\Client\Model\Category**](Category.md) |  | [optional]
+**photo_urls** | **string[]** |  |
+**tags** | [**\OpenAPI\Client\Model\Tag[]**](Tag.md) |  | [optional]
+**status** | **string** | pet status in the store | [optional]
+
+[[Back to Model list]](../../README.md#models) [[Back to API list]](../../README.md#endpoints) [[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/docs/Model/Query.md

@@ -0,0 +1,10 @@
+# # Query
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**id** | **int** | Query | [optional]
+**outcomes** | **string[]** |  | [optional]
+
+[[Back to Model list]](../../README.md#models) [[Back to API list]](../../README.md#endpoints) [[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/docs/Model/StringEnumRef.md

@@ -0,0 +1,8 @@
+# # StringEnumRef
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+
+[[Back to Model list]](../../README.md#models) [[Back to API list]](../../README.md#endpoints) [[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/docs/Model/Tag.md

@@ -0,0 +1,10 @@
+# # Tag
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**id** | **int** |  | [optional]
+**name** | **string** |  | [optional]
+
+[[Back to Model list]](../../README.md#models) [[Back to API list]](../../README.md#endpoints) [[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/docs/Model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.md

@@ -0,0 +1,12 @@
+# # TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**size** | **string** |  | [optional]
+**color** | **string** |  | [optional]
+**id** | **int** |  | [optional]
+**name** | **string** |  | [optional]
+
+[[Back to Model list]](../../README.md#models) [[Back to API list]](../../README.md#endpoints) [[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/docs/Model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.md

@@ -0,0 +1,9 @@
+# # TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**values** | **string[]** |  | [optional]
+
+[[Back to Model list]](../../README.md#models) [[Back to API list]](../../README.md#endpoints) [[Back to README]](../../README.md)

samples/client/echo_api/php-nextgen/git_push.sh

@@ -0,0 +1,57 @@
+#!/bin/sh
+# ref: https://help.github.com/articles/adding-an-existing-project-to-github-using-the-command-line/
+#
+# Usage example: /bin/sh ./git_push.sh wing328 openapi-petstore-perl "minor update" "gitlab.com"
+
+git_user_id=$1
+git_repo_id=$2
+release_note=$3
+git_host=$4
+
+if [ "$git_host" = "" ]; then
+    git_host="github.com"
+    echo "[INFO] No command line input provided. Set \$git_host to $git_host"
+fi
+
+if [ "$git_user_id" = "" ]; then
+    git_user_id="GIT_USER_ID"
+    echo "[INFO] No command line input provided. Set \$git_user_id to $git_user_id"
+fi
+
+if [ "$git_repo_id" = "" ]; then
+    git_repo_id="GIT_REPO_ID"
+    echo "[INFO] No command line input provided. Set \$git_repo_id to $git_repo_id"
+fi
+
+if [ "$release_note" = "" ]; then
+    release_note="Minor update"
+    echo "[INFO] No command line input provided. Set \$release_note to $release_note"
+fi
+
+# Initialize the local directory as a Git repository
+git init
+
+# Adds the files in the local repository and stages them for commit.
+git add .
+
+# Commits the tracked changes and prepares them to be pushed to a remote repository.
+git commit -m "$release_note"
+
+# Sets the new remote
+git_remote=$(git remote)
+if [ "$git_remote" = "" ]; then # git remote not defined
+
+    if [ "$GIT_TOKEN" = "" ]; then
+        echo "[INFO] \$GIT_TOKEN (environment variable) is not set. Using the git credential in your environment."
+        git remote add origin https://${git_host}/${git_user_id}/${git_repo_id}.git
+    else
+        git remote add origin https://${git_user_id}:"${GIT_TOKEN}"@${git_host}/${git_user_id}/${git_repo_id}.git
+    fi
+
+fi
+
+git pull origin master
+
+# Pushes (Forces) the changes in the local repository up to the remote repository
+echo "Git pushing to https://${git_host}/${git_user_id}/${git_repo_id}.git"
+git push origin master 2>&1 | grep -v 'To https'

samples/client/echo_api/php-nextgen/phpunit.xml.dist

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" bootstrap="./vendor/autoload.php" colors="true" convertErrorsToExceptions="true" convertNoticesToExceptions="true" convertWarningsToExceptions="true" stopOnFailure="false" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd">
+  <coverage processUncoveredFiles="true">
+    <include>
+      <directory suffix=".php">./src/Api</directory>
+      <directory suffix=".php">./src/Model</directory>
+    </include>
+  </coverage>
+  <testsuites>
+    <testsuite name="tests">
+      <directory>./tests/Api</directory>
+      <directory>./tests/Model</directory>
+    </testsuite>
+  </testsuites>
+  <php>
+    <ini name="error_reporting" value="E_ALL"/>
+  </php>
+</phpunit>

samples/client/echo_api/php-nextgen/src/Api/AuthApi.php

@@ -0,0 +1,411 @@
+<?php
+/**
+ * AuthApi
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client\Api;
+
+use GuzzleHttp\Client;
+use GuzzleHttp\ClientInterface;
+use GuzzleHttp\Exception\ConnectException;
+use GuzzleHttp\Exception\RequestException;
+use GuzzleHttp\Psr7\MultipartStream;
+use GuzzleHttp\Psr7\Request;
+use GuzzleHttp\RequestOptions;
+use OpenAPI\Client\ApiException;
+use OpenAPI\Client\Configuration;
+use OpenAPI\Client\HeaderSelector;
+use OpenAPI\Client\ObjectSerializer;
+
+/**
+ * AuthApi Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+class AuthApi
+{
+    /**
+     * @var ClientInterface
+     */
+    protected $client;
+
+    /**
+     * @var Configuration
+     */
+    protected $config;
+
+    /**
+     * @var HeaderSelector
+     */
+    protected $headerSelector;
+
+    /**
+     * @var int Host index
+     */
+    protected $hostIndex;
+
+    /** @var string[] $contentTypes **/
+    public const contentTypes = [
+        'testAuthHttpBasic' => [
+            'application/json',
+        ],
+    ];
+
+/**
+     * @param ClientInterface $client
+     * @param Configuration   $config
+     * @param HeaderSelector  $selector
+     * @param int             $hostIndex (Optional) host index to select the list of hosts if defined in the OpenAPI spec
+     */
+    public function __construct(
+        ClientInterface $client = null,
+        Configuration $config = null,
+        HeaderSelector $selector = null,
+        $hostIndex = 0
+    ) {
+        $this->client = $client ?: new Client();
+        $this->config = $config ?: new Configuration();
+        $this->headerSelector = $selector ?: new HeaderSelector();
+        $this->hostIndex = $hostIndex;
+    }
+
+    /**
+     * Set the host index
+     *
+     * @param int $hostIndex Host index (required)
+     */
+    public function setHostIndex($hostIndex): void
+    {
+        $this->hostIndex = $hostIndex;
+    }
+
+    /**
+     * Get the host index
+     *
+     * @return int Host index
+     */
+    public function getHostIndex()
+    {
+        return $this->hostIndex;
+    }
+
+    /**
+     * @return Configuration
+     */
+    public function getConfig()
+    {
+        return $this->config;
+    }
+
+    /**
+     * Operation testAuthHttpBasic
+     *
+     * To test HTTP basic authentication
+     *
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testAuthHttpBasic'] to see the possible values for this operation
+     *
+     * @throws \OpenAPI\Client\ApiException on non-2xx response
+     * @throws \InvalidArgumentException
+     * @return string
+     */
+    public function testAuthHttpBasic(string $contentType = self::contentTypes['testAuthHttpBasic'][0])
+    {
+        list($response) = $this->testAuthHttpBasicWithHttpInfo($contentType);
+        return $response;
+    }
+
+    /**
+     * Operation testAuthHttpBasicWithHttpInfo
+     *
+     * To test HTTP basic authentication
+     *
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testAuthHttpBasic'] to see the possible values for this operation
+     *
+     * @throws \OpenAPI\Client\ApiException on non-2xx response
+     * @throws \InvalidArgumentException
+     * @return array of string, HTTP status code, HTTP response headers (array of strings)
+     */
+    public function testAuthHttpBasicWithHttpInfo(string $contentType = self::contentTypes['testAuthHttpBasic'][0])
+    {
+        $request = $this->testAuthHttpBasicRequest($contentType);
+
+        try {
+            $options = $this->createHttpClientOption();
+            try {
+                $response = $this->client->send($request, $options);
+            } catch (RequestException $e) {
+                throw new ApiException(
+                    "[{$e->getCode()}] {$e->getMessage()}",
+                    (int) $e->getCode(),
+                    $e->getResponse() ? $e->getResponse()->getHeaders() : null,
+                    $e->getResponse() ? (string) $e->getResponse()->getBody() : null
+                );
+            } catch (ConnectException $e) {
+                throw new ApiException(
+                    "[{$e->getCode()}] {$e->getMessage()}",
+                    (int) $e->getCode(),
+                    null,
+                    null
+                );
+            }
+
+            $statusCode = $response->getStatusCode();
+
+            if ($statusCode < 200 || $statusCode > 299) {
+                throw new ApiException(
+                    sprintf(
+                        '[%d] Error connecting to the API (%s)',
+                        $statusCode,
+                        (string) $request->getUri()
+                    ),
+                    $statusCode,
+                    $response->getHeaders(),
+                    (string) $response->getBody()
+                );
+            }
+
+            switch($statusCode) {
+                case 200:
+                    if ('string' === '\SplFileObject') {
+                        $content = $response->getBody(); //stream goes to serializer
+                    } else {
+                        $content = (string) $response->getBody();
+                        if ('string' !== 'string') {
+                            $content = json_decode($content);
+                        }
+                    }
+
+                    return [
+                        ObjectSerializer::deserialize($content, 'string', []),
+                        $response->getStatusCode(),
+                        $response->getHeaders()
+                    ];
+            }
+
+            $returnType = 'string';
+            if ($returnType === '\SplFileObject') {
+                $content = $response->getBody(); //stream goes to serializer
+            } else {
+                $content = (string) $response->getBody();
+                if ($returnType !== 'string') {
+                    $content = json_decode($content);
+                }
+            }
+
+            return [
+                ObjectSerializer::deserialize($content, $returnType, []),
+                $response->getStatusCode(),
+                $response->getHeaders()
+            ];
+
+        } catch (ApiException $e) {
+            switch ($e->getCode()) {
+                case 200:
+                    $data = ObjectSerializer::deserialize(
+                        $e->getResponseBody(),
+                        'string',
+                        $e->getResponseHeaders()
+                    );
+                    $e->setResponseObject($data);
+                    break;
+            }
+            throw $e;
+        }
+    }
+
+    /**
+     * Operation testAuthHttpBasicAsync
+     *
+     * To test HTTP basic authentication
+     *
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testAuthHttpBasic'] to see the possible values for this operation
+     *
+     * @throws \InvalidArgumentException
+     * @return \GuzzleHttp\Promise\PromiseInterface
+     */
+    public function testAuthHttpBasicAsync(string $contentType = self::contentTypes['testAuthHttpBasic'][0])
+    {
+        return $this->testAuthHttpBasicAsyncWithHttpInfo($contentType)
+            ->then(
+                function ($response) {
+                    return $response[0];
+                }
+            );
+    }
+
+    /**
+     * Operation testAuthHttpBasicAsyncWithHttpInfo
+     *
+     * To test HTTP basic authentication
+     *
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testAuthHttpBasic'] to see the possible values for this operation
+     *
+     * @throws \InvalidArgumentException
+     * @return \GuzzleHttp\Promise\PromiseInterface
+     */
+    public function testAuthHttpBasicAsyncWithHttpInfo(string $contentType = self::contentTypes['testAuthHttpBasic'][0])
+    {
+        $returnType = 'string';
+        $request = $this->testAuthHttpBasicRequest($contentType);
+
+        return $this->client
+            ->sendAsync($request, $this->createHttpClientOption())
+            ->then(
+                function ($response) use ($returnType) {
+                    if ($returnType === '\SplFileObject') {
+                        $content = $response->getBody(); //stream goes to serializer
+                    } else {
+                        $content = (string) $response->getBody();
+                        if ($returnType !== 'string') {
+                            $content = json_decode($content);
+                        }
+                    }
+
+                    return [
+                        ObjectSerializer::deserialize($content, $returnType, []),
+                        $response->getStatusCode(),
+                        $response->getHeaders()
+                    ];
+                },
+                function ($exception) {
+                    $response = $exception->getResponse();
+                    $statusCode = $response->getStatusCode();
+                    throw new ApiException(
+                        sprintf(
+                            '[%d] Error connecting to the API (%s)',
+                            $statusCode,
+                            $exception->getRequest()->getUri()
+                        ),
+                        $statusCode,
+                        $response->getHeaders(),
+                        (string) $response->getBody()
+                    );
+                }
+            );
+    }
+
+    /**
+     * Create request for operation 'testAuthHttpBasic'
+     *
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testAuthHttpBasic'] to see the possible values for this operation
+     *
+     * @throws \InvalidArgumentException
+     * @return \GuzzleHttp\Psr7\Request
+     */
+    public function testAuthHttpBasicRequest(string $contentType = self::contentTypes['testAuthHttpBasic'][0])
+    {
+
+
+        $resourcePath = '/auth/http/basic';
+        $formParams = [];
+        $queryParams = [];
+        $headerParams = [];
+        $httpBody = '';
+        $multipart = false;
+
+
+
+
+
+        $headers = $this->headerSelector->selectHeaders(
+            ['text/plain', ],
+            $contentType,
+            $multipart
+        );
+
+        // for model (json/xml)
+        if (count($formParams) > 0) {
+            if ($multipart) {
+                $multipartContents = [];
+                foreach ($formParams as $formParamName => $formParamValue) {
+                    $formParamValueItems = is_array($formParamValue) ? $formParamValue : [$formParamValue];
+                    foreach ($formParamValueItems as $formParamValueItem) {
+                        $multipartContents[] = [
+                            'name' => $formParamName,
+                            'contents' => $formParamValueItem
+                        ];
+                    }
+                }
+                // for HTTP post (form)
+                $httpBody = new MultipartStream($multipartContents);
+
+            } elseif (stripos($headers['Content-Type'], 'application/json') !== false) {
+                # if Content-Type contains "application/json", json_encode the form parameters
+                $httpBody = \GuzzleHttp\Utils::jsonEncode($formParams);
+            } else {
+                // for HTTP post (form)
+                $httpBody = ObjectSerializer::buildQuery($formParams);
+            }
+        }
+
+        // this endpoint requires HTTP basic authentication
+        if (!empty($this->config->getUsername()) || !(empty($this->config->getPassword()))) {
+            $headers['Authorization'] = 'Basic ' . base64_encode($this->config->getUsername() . ":" . $this->config->getPassword());
+        }
+
+        $defaultHeaders = [];
+        if ($this->config->getUserAgent()) {
+            $defaultHeaders['User-Agent'] = $this->config->getUserAgent();
+        }
+
+        $headers = array_merge(
+            $defaultHeaders,
+            $headerParams,
+            $headers
+        );
+
+        $operationHost = $this->config->getHost();
+        $query = ObjectSerializer::buildQuery($queryParams);
+        return new Request(
+            'POST',
+            $operationHost . $resourcePath . ($query ? "?{$query}" : ''),
+            $headers,
+            $httpBody
+        );
+    }
+
+    /**
+     * Create http client option
+     *
+     * @throws \RuntimeException on file opening failure
+     * @return array of http client options
+     */
+    protected function createHttpClientOption()
+    {
+        $options = [];
+        if ($this->config->getDebug()) {
+            $options[RequestOptions::DEBUG] = fopen($this->config->getDebugFile(), 'a');
+            if (!$options[RequestOptions::DEBUG]) {
+                throw new \RuntimeException('Failed to open the debug file: ' . $this->config->getDebugFile());
+            }
+        }
+
+        return $options;
+    }
+}

samples/client/echo_api/php-nextgen/src/Api/FormApi.php

@@ -0,0 +1,763 @@
+<?php
+/**
+ * FormApi
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client\Api;
+
+use GuzzleHttp\Client;
+use GuzzleHttp\ClientInterface;
+use GuzzleHttp\Exception\ConnectException;
+use GuzzleHttp\Exception\RequestException;
+use GuzzleHttp\Psr7\MultipartStream;
+use GuzzleHttp\Psr7\Request;
+use GuzzleHttp\RequestOptions;
+use OpenAPI\Client\ApiException;
+use OpenAPI\Client\Configuration;
+use OpenAPI\Client\HeaderSelector;
+use OpenAPI\Client\ObjectSerializer;
+
+/**
+ * FormApi Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+class FormApi
+{
+    /**
+     * @var ClientInterface
+     */
+    protected $client;
+
+    /**
+     * @var Configuration
+     */
+    protected $config;
+
+    /**
+     * @var HeaderSelector
+     */
+    protected $headerSelector;
+
+    /**
+     * @var int Host index
+     */
+    protected $hostIndex;
+
+    /** @var string[] $contentTypes **/
+    public const contentTypes = [
+        'testFormIntegerBooleanString' => [
+            'application/x-www-form-urlencoded',
+        ],
+        'testFormOneof' => [
+            'application/x-www-form-urlencoded',
+        ],
+    ];
+
+/**
+     * @param ClientInterface $client
+     * @param Configuration   $config
+     * @param HeaderSelector  $selector
+     * @param int             $hostIndex (Optional) host index to select the list of hosts if defined in the OpenAPI spec
+     */
+    public function __construct(
+        ClientInterface $client = null,
+        Configuration $config = null,
+        HeaderSelector $selector = null,
+        $hostIndex = 0
+    ) {
+        $this->client = $client ?: new Client();
+        $this->config = $config ?: new Configuration();
+        $this->headerSelector = $selector ?: new HeaderSelector();
+        $this->hostIndex = $hostIndex;
+    }
+
+    /**
+     * Set the host index
+     *
+     * @param int $hostIndex Host index (required)
+     */
+    public function setHostIndex($hostIndex): void
+    {
+        $this->hostIndex = $hostIndex;
+    }
+
+    /**
+     * Get the host index
+     *
+     * @return int Host index
+     */
+    public function getHostIndex()
+    {
+        return $this->hostIndex;
+    }
+
+    /**
+     * @return Configuration
+     */
+    public function getConfig()
+    {
+        return $this->config;
+    }
+
+    /**
+     * Operation testFormIntegerBooleanString
+     *
+     * Test form parameter(s)
+     *
+     * @param  int $integer_form integer_form (optional)
+     * @param  bool $boolean_form boolean_form (optional)
+     * @param  string $string_form string_form (optional)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testFormIntegerBooleanString'] to see the possible values for this operation
+     *
+     * @throws \OpenAPI\Client\ApiException on non-2xx response
+     * @throws \InvalidArgumentException
+     * @return string
+     */
+    public function testFormIntegerBooleanString($integer_form = null, $boolean_form = null, $string_form = null, string $contentType = self::contentTypes['testFormIntegerBooleanString'][0])
+    {
+        list($response) = $this->testFormIntegerBooleanStringWithHttpInfo($integer_form, $boolean_form, $string_form, $contentType);
+        return $response;
+    }
+
+    /**
+     * Operation testFormIntegerBooleanStringWithHttpInfo
+     *
+     * Test form parameter(s)
+     *
+     * @param  int $integer_form (optional)
+     * @param  bool $boolean_form (optional)
+     * @param  string $string_form (optional)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testFormIntegerBooleanString'] to see the possible values for this operation
+     *
+     * @throws \OpenAPI\Client\ApiException on non-2xx response
+     * @throws \InvalidArgumentException
+     * @return array of string, HTTP status code, HTTP response headers (array of strings)
+     */
+    public function testFormIntegerBooleanStringWithHttpInfo($integer_form = null, $boolean_form = null, $string_form = null, string $contentType = self::contentTypes['testFormIntegerBooleanString'][0])
+    {
+        $request = $this->testFormIntegerBooleanStringRequest($integer_form, $boolean_form, $string_form, $contentType);
+
+        try {
+            $options = $this->createHttpClientOption();
+            try {
+                $response = $this->client->send($request, $options);
+            } catch (RequestException $e) {
+                throw new ApiException(
+                    "[{$e->getCode()}] {$e->getMessage()}",
+                    (int) $e->getCode(),
+                    $e->getResponse() ? $e->getResponse()->getHeaders() : null,
+                    $e->getResponse() ? (string) $e->getResponse()->getBody() : null
+                );
+            } catch (ConnectException $e) {
+                throw new ApiException(
+                    "[{$e->getCode()}] {$e->getMessage()}",
+                    (int) $e->getCode(),
+                    null,
+                    null
+                );
+            }
+
+            $statusCode = $response->getStatusCode();
+
+            if ($statusCode < 200 || $statusCode > 299) {
+                throw new ApiException(
+                    sprintf(
+                        '[%d] Error connecting to the API (%s)',
+                        $statusCode,
+                        (string) $request->getUri()
+                    ),
+                    $statusCode,
+                    $response->getHeaders(),
+                    (string) $response->getBody()
+                );
+            }
+
+            switch($statusCode) {
+                case 200:
+                    if ('string' === '\SplFileObject') {
+                        $content = $response->getBody(); //stream goes to serializer
+                    } else {
+                        $content = (string) $response->getBody();
+                        if ('string' !== 'string') {
+                            $content = json_decode($content);
+                        }
+                    }
+
+                    return [
+                        ObjectSerializer::deserialize($content, 'string', []),
+                        $response->getStatusCode(),
+                        $response->getHeaders()
+                    ];
+            }
+
+            $returnType = 'string';
+            if ($returnType === '\SplFileObject') {
+                $content = $response->getBody(); //stream goes to serializer
+            } else {
+                $content = (string) $response->getBody();
+                if ($returnType !== 'string') {
+                    $content = json_decode($content);
+                }
+            }
+
+            return [
+                ObjectSerializer::deserialize($content, $returnType, []),
+                $response->getStatusCode(),
+                $response->getHeaders()
+            ];
+
+        } catch (ApiException $e) {
+            switch ($e->getCode()) {
+                case 200:
+                    $data = ObjectSerializer::deserialize(
+                        $e->getResponseBody(),
+                        'string',
+                        $e->getResponseHeaders()
+                    );
+                    $e->setResponseObject($data);
+                    break;
+            }
+            throw $e;
+        }
+    }
+
+    /**
+     * Operation testFormIntegerBooleanStringAsync
+     *
+     * Test form parameter(s)
+     *
+     * @param  int $integer_form (optional)
+     * @param  bool $boolean_form (optional)
+     * @param  string $string_form (optional)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testFormIntegerBooleanString'] to see the possible values for this operation
+     *
+     * @throws \InvalidArgumentException
+     * @return \GuzzleHttp\Promise\PromiseInterface
+     */
+    public function testFormIntegerBooleanStringAsync($integer_form = null, $boolean_form = null, $string_form = null, string $contentType = self::contentTypes['testFormIntegerBooleanString'][0])
+    {
+        return $this->testFormIntegerBooleanStringAsyncWithHttpInfo($integer_form, $boolean_form, $string_form, $contentType)
+            ->then(
+                function ($response) {
+                    return $response[0];
+                }
+            );
+    }
+
+    /**
+     * Operation testFormIntegerBooleanStringAsyncWithHttpInfo
+     *
+     * Test form parameter(s)
+     *
+     * @param  int $integer_form (optional)
+     * @param  bool $boolean_form (optional)
+     * @param  string $string_form (optional)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testFormIntegerBooleanString'] to see the possible values for this operation
+     *
+     * @throws \InvalidArgumentException
+     * @return \GuzzleHttp\Promise\PromiseInterface
+     */
+    public function testFormIntegerBooleanStringAsyncWithHttpInfo($integer_form = null, $boolean_form = null, $string_form = null, string $contentType = self::contentTypes['testFormIntegerBooleanString'][0])
+    {
+        $returnType = 'string';
+        $request = $this->testFormIntegerBooleanStringRequest($integer_form, $boolean_form, $string_form, $contentType);
+
+        return $this->client
+            ->sendAsync($request, $this->createHttpClientOption())
+            ->then(
+                function ($response) use ($returnType) {
+                    if ($returnType === '\SplFileObject') {
+                        $content = $response->getBody(); //stream goes to serializer
+                    } else {
+                        $content = (string) $response->getBody();
+                        if ($returnType !== 'string') {
+                            $content = json_decode($content);
+                        }
+                    }
+
+                    return [
+                        ObjectSerializer::deserialize($content, $returnType, []),
+                        $response->getStatusCode(),
+                        $response->getHeaders()
+                    ];
+                },
+                function ($exception) {
+                    $response = $exception->getResponse();
+                    $statusCode = $response->getStatusCode();
+                    throw new ApiException(
+                        sprintf(
+                            '[%d] Error connecting to the API (%s)',
+                            $statusCode,
+                            $exception->getRequest()->getUri()
+                        ),
+                        $statusCode,
+                        $response->getHeaders(),
+                        (string) $response->getBody()
+                    );
+                }
+            );
+    }
+
+    /**
+     * Create request for operation 'testFormIntegerBooleanString'
+     *
+     * @param  int $integer_form (optional)
+     * @param  bool $boolean_form (optional)
+     * @param  string $string_form (optional)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testFormIntegerBooleanString'] to see the possible values for this operation
+     *
+     * @throws \InvalidArgumentException
+     * @return \GuzzleHttp\Psr7\Request
+     */
+    public function testFormIntegerBooleanStringRequest($integer_form = null, $boolean_form = null, $string_form = null, string $contentType = self::contentTypes['testFormIntegerBooleanString'][0])
+    {
+
+
+
+
+
+        $resourcePath = '/form/integer/boolean/string';
+        $formParams = [];
+        $queryParams = [];
+        $headerParams = [];
+        $httpBody = '';
+        $multipart = false;
+
+
+
+
+        // form params
+        if ($integer_form !== null) {
+            $formParams['integer_form'] = ObjectSerializer::toFormValue($integer_form);
+        }
+        // form params
+        if ($boolean_form !== null) {
+            $formParams['boolean_form'] = ObjectSerializer::toFormValue($boolean_form);
+        }
+        // form params
+        if ($string_form !== null) {
+            $formParams['string_form'] = ObjectSerializer::toFormValue($string_form);
+        }
+
+        $headers = $this->headerSelector->selectHeaders(
+            ['text/plain', ],
+            $contentType,
+            $multipart
+        );
+
+        // for model (json/xml)
+        if (count($formParams) > 0) {
+            if ($multipart) {
+                $multipartContents = [];
+                foreach ($formParams as $formParamName => $formParamValue) {
+                    $formParamValueItems = is_array($formParamValue) ? $formParamValue : [$formParamValue];
+                    foreach ($formParamValueItems as $formParamValueItem) {
+                        $multipartContents[] = [
+                            'name' => $formParamName,
+                            'contents' => $formParamValueItem
+                        ];
+                    }
+                }
+                // for HTTP post (form)
+                $httpBody = new MultipartStream($multipartContents);
+
+            } elseif (stripos($headers['Content-Type'], 'application/json') !== false) {
+                # if Content-Type contains "application/json", json_encode the form parameters
+                $httpBody = \GuzzleHttp\Utils::jsonEncode($formParams);
+            } else {
+                // for HTTP post (form)
+                $httpBody = ObjectSerializer::buildQuery($formParams);
+            }
+        }
+
+
+        $defaultHeaders = [];
+        if ($this->config->getUserAgent()) {
+            $defaultHeaders['User-Agent'] = $this->config->getUserAgent();
+        }
+
+        $headers = array_merge(
+            $defaultHeaders,
+            $headerParams,
+            $headers
+        );
+
+        $operationHost = $this->config->getHost();
+        $query = ObjectSerializer::buildQuery($queryParams);
+        return new Request(
+            'POST',
+            $operationHost . $resourcePath . ($query ? "?{$query}" : ''),
+            $headers,
+            $httpBody
+        );
+    }
+
+    /**
+     * Operation testFormOneof
+     *
+     * Test form parameter(s) for oneOf schema
+     *
+     * @param  string $form1 form1 (optional)
+     * @param  int $form2 form2 (optional)
+     * @param  string $form3 form3 (optional)
+     * @param  bool $form4 form4 (optional)
+     * @param  int $id id (optional)
+     * @param  string $name name (optional)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testFormOneof'] to see the possible values for this operation
+     *
+     * @throws \OpenAPI\Client\ApiException on non-2xx response
+     * @throws \InvalidArgumentException
+     * @return string
+     */
+    public function testFormOneof($form1 = null, $form2 = null, $form3 = null, $form4 = null, $id = null, $name = null, string $contentType = self::contentTypes['testFormOneof'][0])
+    {
+        list($response) = $this->testFormOneofWithHttpInfo($form1, $form2, $form3, $form4, $id, $name, $contentType);
+        return $response;
+    }
+
+    /**
+     * Operation testFormOneofWithHttpInfo
+     *
+     * Test form parameter(s) for oneOf schema
+     *
+     * @param  string $form1 (optional)
+     * @param  int $form2 (optional)
+     * @param  string $form3 (optional)
+     * @param  bool $form4 (optional)
+     * @param  int $id (optional)
+     * @param  string $name (optional)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testFormOneof'] to see the possible values for this operation
+     *
+     * @throws \OpenAPI\Client\ApiException on non-2xx response
+     * @throws \InvalidArgumentException
+     * @return array of string, HTTP status code, HTTP response headers (array of strings)
+     */
+    public function testFormOneofWithHttpInfo($form1 = null, $form2 = null, $form3 = null, $form4 = null, $id = null, $name = null, string $contentType = self::contentTypes['testFormOneof'][0])
+    {
+        $request = $this->testFormOneofRequest($form1, $form2, $form3, $form4, $id, $name, $contentType);
+
+        try {
+            $options = $this->createHttpClientOption();
+            try {
+                $response = $this->client->send($request, $options);
+            } catch (RequestException $e) {
+                throw new ApiException(
+                    "[{$e->getCode()}] {$e->getMessage()}",
+                    (int) $e->getCode(),
+                    $e->getResponse() ? $e->getResponse()->getHeaders() : null,
+                    $e->getResponse() ? (string) $e->getResponse()->getBody() : null
+                );
+            } catch (ConnectException $e) {
+                throw new ApiException(
+                    "[{$e->getCode()}] {$e->getMessage()}",
+                    (int) $e->getCode(),
+                    null,
+                    null
+                );
+            }
+
+            $statusCode = $response->getStatusCode();
+
+            if ($statusCode < 200 || $statusCode > 299) {
+                throw new ApiException(
+                    sprintf(
+                        '[%d] Error connecting to the API (%s)',
+                        $statusCode,
+                        (string) $request->getUri()
+                    ),
+                    $statusCode,
+                    $response->getHeaders(),
+                    (string) $response->getBody()
+                );
+            }
+
+            switch($statusCode) {
+                case 200:
+                    if ('string' === '\SplFileObject') {
+                        $content = $response->getBody(); //stream goes to serializer
+                    } else {
+                        $content = (string) $response->getBody();
+                        if ('string' !== 'string') {
+                            $content = json_decode($content);
+                        }
+                    }
+
+                    return [
+                        ObjectSerializer::deserialize($content, 'string', []),
+                        $response->getStatusCode(),
+                        $response->getHeaders()
+                    ];
+            }
+
+            $returnType = 'string';
+            if ($returnType === '\SplFileObject') {
+                $content = $response->getBody(); //stream goes to serializer
+            } else {
+                $content = (string) $response->getBody();
+                if ($returnType !== 'string') {
+                    $content = json_decode($content);
+                }
+            }
+
+            return [
+                ObjectSerializer::deserialize($content, $returnType, []),
+                $response->getStatusCode(),
+                $response->getHeaders()
+            ];
+
+        } catch (ApiException $e) {
+            switch ($e->getCode()) {
+                case 200:
+                    $data = ObjectSerializer::deserialize(
+                        $e->getResponseBody(),
+                        'string',
+                        $e->getResponseHeaders()
+                    );
+                    $e->setResponseObject($data);
+                    break;
+            }
+            throw $e;
+        }
+    }
+
+    /**
+     * Operation testFormOneofAsync
+     *
+     * Test form parameter(s) for oneOf schema
+     *
+     * @param  string $form1 (optional)
+     * @param  int $form2 (optional)
+     * @param  string $form3 (optional)
+     * @param  bool $form4 (optional)
+     * @param  int $id (optional)
+     * @param  string $name (optional)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testFormOneof'] to see the possible values for this operation
+     *
+     * @throws \InvalidArgumentException
+     * @return \GuzzleHttp\Promise\PromiseInterface
+     */
+    public function testFormOneofAsync($form1 = null, $form2 = null, $form3 = null, $form4 = null, $id = null, $name = null, string $contentType = self::contentTypes['testFormOneof'][0])
+    {
+        return $this->testFormOneofAsyncWithHttpInfo($form1, $form2, $form3, $form4, $id, $name, $contentType)
+            ->then(
+                function ($response) {
+                    return $response[0];
+                }
+            );
+    }
+
+    /**
+     * Operation testFormOneofAsyncWithHttpInfo
+     *
+     * Test form parameter(s) for oneOf schema
+     *
+     * @param  string $form1 (optional)
+     * @param  int $form2 (optional)
+     * @param  string $form3 (optional)
+     * @param  bool $form4 (optional)
+     * @param  int $id (optional)
+     * @param  string $name (optional)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testFormOneof'] to see the possible values for this operation
+     *
+     * @throws \InvalidArgumentException
+     * @return \GuzzleHttp\Promise\PromiseInterface
+     */
+    public function testFormOneofAsyncWithHttpInfo($form1 = null, $form2 = null, $form3 = null, $form4 = null, $id = null, $name = null, string $contentType = self::contentTypes['testFormOneof'][0])
+    {
+        $returnType = 'string';
+        $request = $this->testFormOneofRequest($form1, $form2, $form3, $form4, $id, $name, $contentType);
+
+        return $this->client
+            ->sendAsync($request, $this->createHttpClientOption())
+            ->then(
+                function ($response) use ($returnType) {
+                    if ($returnType === '\SplFileObject') {
+                        $content = $response->getBody(); //stream goes to serializer
+                    } else {
+                        $content = (string) $response->getBody();
+                        if ($returnType !== 'string') {
+                            $content = json_decode($content);
+                        }
+                    }
+
+                    return [
+                        ObjectSerializer::deserialize($content, $returnType, []),
+                        $response->getStatusCode(),
+                        $response->getHeaders()
+                    ];
+                },
+                function ($exception) {
+                    $response = $exception->getResponse();
+                    $statusCode = $response->getStatusCode();
+                    throw new ApiException(
+                        sprintf(
+                            '[%d] Error connecting to the API (%s)',
+                            $statusCode,
+                            $exception->getRequest()->getUri()
+                        ),
+                        $statusCode,
+                        $response->getHeaders(),
+                        (string) $response->getBody()
+                    );
+                }
+            );
+    }
+
+    /**
+     * Create request for operation 'testFormOneof'
+     *
+     * @param  string $form1 (optional)
+     * @param  int $form2 (optional)
+     * @param  string $form3 (optional)
+     * @param  bool $form4 (optional)
+     * @param  int $id (optional)
+     * @param  string $name (optional)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testFormOneof'] to see the possible values for this operation
+     *
+     * @throws \InvalidArgumentException
+     * @return \GuzzleHttp\Psr7\Request
+     */
+    public function testFormOneofRequest($form1 = null, $form2 = null, $form3 = null, $form4 = null, $id = null, $name = null, string $contentType = self::contentTypes['testFormOneof'][0])
+    {
+
+
+
+
+
+
+
+
+        $resourcePath = '/form/oneof';
+        $formParams = [];
+        $queryParams = [];
+        $headerParams = [];
+        $httpBody = '';
+        $multipart = false;
+
+
+
+
+        // form params
+        if ($form1 !== null) {
+            $formParams['form1'] = ObjectSerializer::toFormValue($form1);
+        }
+        // form params
+        if ($form2 !== null) {
+            $formParams['form2'] = ObjectSerializer::toFormValue($form2);
+        }
+        // form params
+        if ($form3 !== null) {
+            $formParams['form3'] = ObjectSerializer::toFormValue($form3);
+        }
+        // form params
+        if ($form4 !== null) {
+            $formParams['form4'] = ObjectSerializer::toFormValue($form4);
+        }
+        // form params
+        if ($id !== null) {
+            $formParams['id'] = ObjectSerializer::toFormValue($id);
+        }
+        // form params
+        if ($name !== null) {
+            $formParams['name'] = ObjectSerializer::toFormValue($name);
+        }
+
+        $headers = $this->headerSelector->selectHeaders(
+            ['text/plain', ],
+            $contentType,
+            $multipart
+        );
+
+        // for model (json/xml)
+        if (count($formParams) > 0) {
+            if ($multipart) {
+                $multipartContents = [];
+                foreach ($formParams as $formParamName => $formParamValue) {
+                    $formParamValueItems = is_array($formParamValue) ? $formParamValue : [$formParamValue];
+                    foreach ($formParamValueItems as $formParamValueItem) {
+                        $multipartContents[] = [
+                            'name' => $formParamName,
+                            'contents' => $formParamValueItem
+                        ];
+                    }
+                }
+                // for HTTP post (form)
+                $httpBody = new MultipartStream($multipartContents);
+
+            } elseif (stripos($headers['Content-Type'], 'application/json') !== false) {
+                # if Content-Type contains "application/json", json_encode the form parameters
+                $httpBody = \GuzzleHttp\Utils::jsonEncode($formParams);
+            } else {
+                // for HTTP post (form)
+                $httpBody = ObjectSerializer::buildQuery($formParams);
+            }
+        }
+
+
+        $defaultHeaders = [];
+        if ($this->config->getUserAgent()) {
+            $defaultHeaders['User-Agent'] = $this->config->getUserAgent();
+        }
+
+        $headers = array_merge(
+            $defaultHeaders,
+            $headerParams,
+            $headers
+        );
+
+        $operationHost = $this->config->getHost();
+        $query = ObjectSerializer::buildQuery($queryParams);
+        return new Request(
+            'POST',
+            $operationHost . $resourcePath . ($query ? "?{$query}" : ''),
+            $headers,
+            $httpBody
+        );
+    }
+
+    /**
+     * Create http client option
+     *
+     * @throws \RuntimeException on file opening failure
+     * @return array of http client options
+     */
+    protected function createHttpClientOption()
+    {
+        $options = [];
+        if ($this->config->getDebug()) {
+            $options[RequestOptions::DEBUG] = fopen($this->config->getDebugFile(), 'a');
+            if (!$options[RequestOptions::DEBUG]) {
+                throw new \RuntimeException('Failed to open the debug file: ' . $this->config->getDebugFile());
+            }
+        }
+
+        return $options;
+    }
+}

samples/client/echo_api/php-nextgen/src/Api/HeaderApi.php

@@ -0,0 +1,437 @@
+<?php
+/**
+ * HeaderApi
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client\Api;
+
+use GuzzleHttp\Client;
+use GuzzleHttp\ClientInterface;
+use GuzzleHttp\Exception\ConnectException;
+use GuzzleHttp\Exception\RequestException;
+use GuzzleHttp\Psr7\MultipartStream;
+use GuzzleHttp\Psr7\Request;
+use GuzzleHttp\RequestOptions;
+use OpenAPI\Client\ApiException;
+use OpenAPI\Client\Configuration;
+use OpenAPI\Client\HeaderSelector;
+use OpenAPI\Client\ObjectSerializer;
+
+/**
+ * HeaderApi Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+class HeaderApi
+{
+    /**
+     * @var ClientInterface
+     */
+    protected $client;
+
+    /**
+     * @var Configuration
+     */
+    protected $config;
+
+    /**
+     * @var HeaderSelector
+     */
+    protected $headerSelector;
+
+    /**
+     * @var int Host index
+     */
+    protected $hostIndex;
+
+    /** @var string[] $contentTypes **/
+    public const contentTypes = [
+        'testHeaderIntegerBooleanString' => [
+            'application/json',
+        ],
+    ];
+
+/**
+     * @param ClientInterface $client
+     * @param Configuration   $config
+     * @param HeaderSelector  $selector
+     * @param int             $hostIndex (Optional) host index to select the list of hosts if defined in the OpenAPI spec
+     */
+    public function __construct(
+        ClientInterface $client = null,
+        Configuration $config = null,
+        HeaderSelector $selector = null,
+        $hostIndex = 0
+    ) {
+        $this->client = $client ?: new Client();
+        $this->config = $config ?: new Configuration();
+        $this->headerSelector = $selector ?: new HeaderSelector();
+        $this->hostIndex = $hostIndex;
+    }
+
+    /**
+     * Set the host index
+     *
+     * @param int $hostIndex Host index (required)
+     */
+    public function setHostIndex($hostIndex): void
+    {
+        $this->hostIndex = $hostIndex;
+    }
+
+    /**
+     * Get the host index
+     *
+     * @return int Host index
+     */
+    public function getHostIndex()
+    {
+        return $this->hostIndex;
+    }
+
+    /**
+     * @return Configuration
+     */
+    public function getConfig()
+    {
+        return $this->config;
+    }
+
+    /**
+     * Operation testHeaderIntegerBooleanString
+     *
+     * Test header parameter(s)
+     *
+     * @param  int $integer_header integer_header (optional)
+     * @param  bool $boolean_header boolean_header (optional)
+     * @param  string $string_header string_header (optional)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testHeaderIntegerBooleanString'] to see the possible values for this operation
+     *
+     * @throws \OpenAPI\Client\ApiException on non-2xx response
+     * @throws \InvalidArgumentException
+     * @return string
+     */
+    public function testHeaderIntegerBooleanString($integer_header = null, $boolean_header = null, $string_header = null, string $contentType = self::contentTypes['testHeaderIntegerBooleanString'][0])
+    {
+        list($response) = $this->testHeaderIntegerBooleanStringWithHttpInfo($integer_header, $boolean_header, $string_header, $contentType);
+        return $response;
+    }
+
+    /**
+     * Operation testHeaderIntegerBooleanStringWithHttpInfo
+     *
+     * Test header parameter(s)
+     *
+     * @param  int $integer_header (optional)
+     * @param  bool $boolean_header (optional)
+     * @param  string $string_header (optional)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testHeaderIntegerBooleanString'] to see the possible values for this operation
+     *
+     * @throws \OpenAPI\Client\ApiException on non-2xx response
+     * @throws \InvalidArgumentException
+     * @return array of string, HTTP status code, HTTP response headers (array of strings)
+     */
+    public function testHeaderIntegerBooleanStringWithHttpInfo($integer_header = null, $boolean_header = null, $string_header = null, string $contentType = self::contentTypes['testHeaderIntegerBooleanString'][0])
+    {
+        $request = $this->testHeaderIntegerBooleanStringRequest($integer_header, $boolean_header, $string_header, $contentType);
+
+        try {
+            $options = $this->createHttpClientOption();
+            try {
+                $response = $this->client->send($request, $options);
+            } catch (RequestException $e) {
+                throw new ApiException(
+                    "[{$e->getCode()}] {$e->getMessage()}",
+                    (int) $e->getCode(),
+                    $e->getResponse() ? $e->getResponse()->getHeaders() : null,
+                    $e->getResponse() ? (string) $e->getResponse()->getBody() : null
+                );
+            } catch (ConnectException $e) {
+                throw new ApiException(
+                    "[{$e->getCode()}] {$e->getMessage()}",
+                    (int) $e->getCode(),
+                    null,
+                    null
+                );
+            }
+
+            $statusCode = $response->getStatusCode();
+
+            if ($statusCode < 200 || $statusCode > 299) {
+                throw new ApiException(
+                    sprintf(
+                        '[%d] Error connecting to the API (%s)',
+                        $statusCode,
+                        (string) $request->getUri()
+                    ),
+                    $statusCode,
+                    $response->getHeaders(),
+                    (string) $response->getBody()
+                );
+            }
+
+            switch($statusCode) {
+                case 200:
+                    if ('string' === '\SplFileObject') {
+                        $content = $response->getBody(); //stream goes to serializer
+                    } else {
+                        $content = (string) $response->getBody();
+                        if ('string' !== 'string') {
+                            $content = json_decode($content);
+                        }
+                    }
+
+                    return [
+                        ObjectSerializer::deserialize($content, 'string', []),
+                        $response->getStatusCode(),
+                        $response->getHeaders()
+                    ];
+            }
+
+            $returnType = 'string';
+            if ($returnType === '\SplFileObject') {
+                $content = $response->getBody(); //stream goes to serializer
+            } else {
+                $content = (string) $response->getBody();
+                if ($returnType !== 'string') {
+                    $content = json_decode($content);
+                }
+            }
+
+            return [
+                ObjectSerializer::deserialize($content, $returnType, []),
+                $response->getStatusCode(),
+                $response->getHeaders()
+            ];
+
+        } catch (ApiException $e) {
+            switch ($e->getCode()) {
+                case 200:
+                    $data = ObjectSerializer::deserialize(
+                        $e->getResponseBody(),
+                        'string',
+                        $e->getResponseHeaders()
+                    );
+                    $e->setResponseObject($data);
+                    break;
+            }
+            throw $e;
+        }
+    }
+
+    /**
+     * Operation testHeaderIntegerBooleanStringAsync
+     *
+     * Test header parameter(s)
+     *
+     * @param  int $integer_header (optional)
+     * @param  bool $boolean_header (optional)
+     * @param  string $string_header (optional)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testHeaderIntegerBooleanString'] to see the possible values for this operation
+     *
+     * @throws \InvalidArgumentException
+     * @return \GuzzleHttp\Promise\PromiseInterface
+     */
+    public function testHeaderIntegerBooleanStringAsync($integer_header = null, $boolean_header = null, $string_header = null, string $contentType = self::contentTypes['testHeaderIntegerBooleanString'][0])
+    {
+        return $this->testHeaderIntegerBooleanStringAsyncWithHttpInfo($integer_header, $boolean_header, $string_header, $contentType)
+            ->then(
+                function ($response) {
+                    return $response[0];
+                }
+            );
+    }
+
+    /**
+     * Operation testHeaderIntegerBooleanStringAsyncWithHttpInfo
+     *
+     * Test header parameter(s)
+     *
+     * @param  int $integer_header (optional)
+     * @param  bool $boolean_header (optional)
+     * @param  string $string_header (optional)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testHeaderIntegerBooleanString'] to see the possible values for this operation
+     *
+     * @throws \InvalidArgumentException
+     * @return \GuzzleHttp\Promise\PromiseInterface
+     */
+    public function testHeaderIntegerBooleanStringAsyncWithHttpInfo($integer_header = null, $boolean_header = null, $string_header = null, string $contentType = self::contentTypes['testHeaderIntegerBooleanString'][0])
+    {
+        $returnType = 'string';
+        $request = $this->testHeaderIntegerBooleanStringRequest($integer_header, $boolean_header, $string_header, $contentType);
+
+        return $this->client
+            ->sendAsync($request, $this->createHttpClientOption())
+            ->then(
+                function ($response) use ($returnType) {
+                    if ($returnType === '\SplFileObject') {
+                        $content = $response->getBody(); //stream goes to serializer
+                    } else {
+                        $content = (string) $response->getBody();
+                        if ($returnType !== 'string') {
+                            $content = json_decode($content);
+                        }
+                    }
+
+                    return [
+                        ObjectSerializer::deserialize($content, $returnType, []),
+                        $response->getStatusCode(),
+                        $response->getHeaders()
+                    ];
+                },
+                function ($exception) {
+                    $response = $exception->getResponse();
+                    $statusCode = $response->getStatusCode();
+                    throw new ApiException(
+                        sprintf(
+                            '[%d] Error connecting to the API (%s)',
+                            $statusCode,
+                            $exception->getRequest()->getUri()
+                        ),
+                        $statusCode,
+                        $response->getHeaders(),
+                        (string) $response->getBody()
+                    );
+                }
+            );
+    }
+
+    /**
+     * Create request for operation 'testHeaderIntegerBooleanString'
+     *
+     * @param  int $integer_header (optional)
+     * @param  bool $boolean_header (optional)
+     * @param  string $string_header (optional)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testHeaderIntegerBooleanString'] to see the possible values for this operation
+     *
+     * @throws \InvalidArgumentException
+     * @return \GuzzleHttp\Psr7\Request
+     */
+    public function testHeaderIntegerBooleanStringRequest($integer_header = null, $boolean_header = null, $string_header = null, string $contentType = self::contentTypes['testHeaderIntegerBooleanString'][0])
+    {
+
+
+
+
+
+        $resourcePath = '/header/integer/boolean/string';
+        $formParams = [];
+        $queryParams = [];
+        $headerParams = [];
+        $httpBody = '';
+        $multipart = false;
+
+
+        // header params
+        if ($integer_header !== null) {
+            $headerParams['integer_header'] = ObjectSerializer::toHeaderValue($integer_header);
+        }
+        // header params
+        if ($boolean_header !== null) {
+            $headerParams['boolean_header'] = ObjectSerializer::toHeaderValue($boolean_header);
+        }
+        // header params
+        if ($string_header !== null) {
+            $headerParams['string_header'] = ObjectSerializer::toHeaderValue($string_header);
+        }
+
+
+
+        $headers = $this->headerSelector->selectHeaders(
+            ['text/plain', ],
+            $contentType,
+            $multipart
+        );
+
+        // for model (json/xml)
+        if (count($formParams) > 0) {
+            if ($multipart) {
+                $multipartContents = [];
+                foreach ($formParams as $formParamName => $formParamValue) {
+                    $formParamValueItems = is_array($formParamValue) ? $formParamValue : [$formParamValue];
+                    foreach ($formParamValueItems as $formParamValueItem) {
+                        $multipartContents[] = [
+                            'name' => $formParamName,
+                            'contents' => $formParamValueItem
+                        ];
+                    }
+                }
+                // for HTTP post (form)
+                $httpBody = new MultipartStream($multipartContents);
+
+            } elseif (stripos($headers['Content-Type'], 'application/json') !== false) {
+                # if Content-Type contains "application/json", json_encode the form parameters
+                $httpBody = \GuzzleHttp\Utils::jsonEncode($formParams);
+            } else {
+                // for HTTP post (form)
+                $httpBody = ObjectSerializer::buildQuery($formParams);
+            }
+        }
+
+
+        $defaultHeaders = [];
+        if ($this->config->getUserAgent()) {
+            $defaultHeaders['User-Agent'] = $this->config->getUserAgent();
+        }
+
+        $headers = array_merge(
+            $defaultHeaders,
+            $headerParams,
+            $headers
+        );
+
+        $operationHost = $this->config->getHost();
+        $query = ObjectSerializer::buildQuery($queryParams);
+        return new Request(
+            'GET',
+            $operationHost . $resourcePath . ($query ? "?{$query}" : ''),
+            $headers,
+            $httpBody
+        );
+    }
+
+    /**
+     * Create http client option
+     *
+     * @throws \RuntimeException on file opening failure
+     * @return array of http client options
+     */
+    protected function createHttpClientOption()
+    {
+        $options = [];
+        if ($this->config->getDebug()) {
+            $options[RequestOptions::DEBUG] = fopen($this->config->getDebugFile(), 'a');
+            if (!$options[RequestOptions::DEBUG]) {
+                throw new \RuntimeException('Failed to open the debug file: ' . $this->config->getDebugFile());
+            }
+        }
+
+        return $options;
+    }
+}

samples/client/echo_api/php-nextgen/src/Api/PathApi.php

@@ -0,0 +1,447 @@
+<?php
+/**
+ * PathApi
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client\Api;
+
+use GuzzleHttp\Client;
+use GuzzleHttp\ClientInterface;
+use GuzzleHttp\Exception\ConnectException;
+use GuzzleHttp\Exception\RequestException;
+use GuzzleHttp\Psr7\MultipartStream;
+use GuzzleHttp\Psr7\Request;
+use GuzzleHttp\RequestOptions;
+use OpenAPI\Client\ApiException;
+use OpenAPI\Client\Configuration;
+use OpenAPI\Client\HeaderSelector;
+use OpenAPI\Client\ObjectSerializer;
+
+/**
+ * PathApi Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+class PathApi
+{
+    /**
+     * @var ClientInterface
+     */
+    protected $client;
+
+    /**
+     * @var Configuration
+     */
+    protected $config;
+
+    /**
+     * @var HeaderSelector
+     */
+    protected $headerSelector;
+
+    /**
+     * @var int Host index
+     */
+    protected $hostIndex;
+
+    /** @var string[] $contentTypes **/
+    public const contentTypes = [
+        'testsPathStringPathStringIntegerPathInteger' => [
+            'application/json',
+        ],
+    ];
+
+/**
+     * @param ClientInterface $client
+     * @param Configuration   $config
+     * @param HeaderSelector  $selector
+     * @param int             $hostIndex (Optional) host index to select the list of hosts if defined in the OpenAPI spec
+     */
+    public function __construct(
+        ClientInterface $client = null,
+        Configuration $config = null,
+        HeaderSelector $selector = null,
+        $hostIndex = 0
+    ) {
+        $this->client = $client ?: new Client();
+        $this->config = $config ?: new Configuration();
+        $this->headerSelector = $selector ?: new HeaderSelector();
+        $this->hostIndex = $hostIndex;
+    }
+
+    /**
+     * Set the host index
+     *
+     * @param int $hostIndex Host index (required)
+     */
+    public function setHostIndex($hostIndex): void
+    {
+        $this->hostIndex = $hostIndex;
+    }
+
+    /**
+     * Get the host index
+     *
+     * @return int Host index
+     */
+    public function getHostIndex()
+    {
+        return $this->hostIndex;
+    }
+
+    /**
+     * @return Configuration
+     */
+    public function getConfig()
+    {
+        return $this->config;
+    }
+
+    /**
+     * Operation testsPathStringPathStringIntegerPathInteger
+     *
+     * Test path parameter(s)
+     *
+     * @param  string $path_string path_string (required)
+     * @param  int $path_integer path_integer (required)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testsPathStringPathStringIntegerPathInteger'] to see the possible values for this operation
+     *
+     * @throws \OpenAPI\Client\ApiException on non-2xx response
+     * @throws \InvalidArgumentException
+     * @return string
+     */
+    public function testsPathStringPathStringIntegerPathInteger($path_string, $path_integer, string $contentType = self::contentTypes['testsPathStringPathStringIntegerPathInteger'][0])
+    {
+        list($response) = $this->testsPathStringPathStringIntegerPathIntegerWithHttpInfo($path_string, $path_integer, $contentType);
+        return $response;
+    }
+
+    /**
+     * Operation testsPathStringPathStringIntegerPathIntegerWithHttpInfo
+     *
+     * Test path parameter(s)
+     *
+     * @param  string $path_string (required)
+     * @param  int $path_integer (required)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testsPathStringPathStringIntegerPathInteger'] to see the possible values for this operation
+     *
+     * @throws \OpenAPI\Client\ApiException on non-2xx response
+     * @throws \InvalidArgumentException
+     * @return array of string, HTTP status code, HTTP response headers (array of strings)
+     */
+    public function testsPathStringPathStringIntegerPathIntegerWithHttpInfo($path_string, $path_integer, string $contentType = self::contentTypes['testsPathStringPathStringIntegerPathInteger'][0])
+    {
+        $request = $this->testsPathStringPathStringIntegerPathIntegerRequest($path_string, $path_integer, $contentType);
+
+        try {
+            $options = $this->createHttpClientOption();
+            try {
+                $response = $this->client->send($request, $options);
+            } catch (RequestException $e) {
+                throw new ApiException(
+                    "[{$e->getCode()}] {$e->getMessage()}",
+                    (int) $e->getCode(),
+                    $e->getResponse() ? $e->getResponse()->getHeaders() : null,
+                    $e->getResponse() ? (string) $e->getResponse()->getBody() : null
+                );
+            } catch (ConnectException $e) {
+                throw new ApiException(
+                    "[{$e->getCode()}] {$e->getMessage()}",
+                    (int) $e->getCode(),
+                    null,
+                    null
+                );
+            }
+
+            $statusCode = $response->getStatusCode();
+
+            if ($statusCode < 200 || $statusCode > 299) {
+                throw new ApiException(
+                    sprintf(
+                        '[%d] Error connecting to the API (%s)',
+                        $statusCode,
+                        (string) $request->getUri()
+                    ),
+                    $statusCode,
+                    $response->getHeaders(),
+                    (string) $response->getBody()
+                );
+            }
+
+            switch($statusCode) {
+                case 200:
+                    if ('string' === '\SplFileObject') {
+                        $content = $response->getBody(); //stream goes to serializer
+                    } else {
+                        $content = (string) $response->getBody();
+                        if ('string' !== 'string') {
+                            $content = json_decode($content);
+                        }
+                    }
+
+                    return [
+                        ObjectSerializer::deserialize($content, 'string', []),
+                        $response->getStatusCode(),
+                        $response->getHeaders()
+                    ];
+            }
+
+            $returnType = 'string';
+            if ($returnType === '\SplFileObject') {
+                $content = $response->getBody(); //stream goes to serializer
+            } else {
+                $content = (string) $response->getBody();
+                if ($returnType !== 'string') {
+                    $content = json_decode($content);
+                }
+            }
+
+            return [
+                ObjectSerializer::deserialize($content, $returnType, []),
+                $response->getStatusCode(),
+                $response->getHeaders()
+            ];
+
+        } catch (ApiException $e) {
+            switch ($e->getCode()) {
+                case 200:
+                    $data = ObjectSerializer::deserialize(
+                        $e->getResponseBody(),
+                        'string',
+                        $e->getResponseHeaders()
+                    );
+                    $e->setResponseObject($data);
+                    break;
+            }
+            throw $e;
+        }
+    }
+
+    /**
+     * Operation testsPathStringPathStringIntegerPathIntegerAsync
+     *
+     * Test path parameter(s)
+     *
+     * @param  string $path_string (required)
+     * @param  int $path_integer (required)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testsPathStringPathStringIntegerPathInteger'] to see the possible values for this operation
+     *
+     * @throws \InvalidArgumentException
+     * @return \GuzzleHttp\Promise\PromiseInterface
+     */
+    public function testsPathStringPathStringIntegerPathIntegerAsync($path_string, $path_integer, string $contentType = self::contentTypes['testsPathStringPathStringIntegerPathInteger'][0])
+    {
+        return $this->testsPathStringPathStringIntegerPathIntegerAsyncWithHttpInfo($path_string, $path_integer, $contentType)
+            ->then(
+                function ($response) {
+                    return $response[0];
+                }
+            );
+    }
+
+    /**
+     * Operation testsPathStringPathStringIntegerPathIntegerAsyncWithHttpInfo
+     *
+     * Test path parameter(s)
+     *
+     * @param  string $path_string (required)
+     * @param  int $path_integer (required)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testsPathStringPathStringIntegerPathInteger'] to see the possible values for this operation
+     *
+     * @throws \InvalidArgumentException
+     * @return \GuzzleHttp\Promise\PromiseInterface
+     */
+    public function testsPathStringPathStringIntegerPathIntegerAsyncWithHttpInfo($path_string, $path_integer, string $contentType = self::contentTypes['testsPathStringPathStringIntegerPathInteger'][0])
+    {
+        $returnType = 'string';
+        $request = $this->testsPathStringPathStringIntegerPathIntegerRequest($path_string, $path_integer, $contentType);
+
+        return $this->client
+            ->sendAsync($request, $this->createHttpClientOption())
+            ->then(
+                function ($response) use ($returnType) {
+                    if ($returnType === '\SplFileObject') {
+                        $content = $response->getBody(); //stream goes to serializer
+                    } else {
+                        $content = (string) $response->getBody();
+                        if ($returnType !== 'string') {
+                            $content = json_decode($content);
+                        }
+                    }
+
+                    return [
+                        ObjectSerializer::deserialize($content, $returnType, []),
+                        $response->getStatusCode(),
+                        $response->getHeaders()
+                    ];
+                },
+                function ($exception) {
+                    $response = $exception->getResponse();
+                    $statusCode = $response->getStatusCode();
+                    throw new ApiException(
+                        sprintf(
+                            '[%d] Error connecting to the API (%s)',
+                            $statusCode,
+                            $exception->getRequest()->getUri()
+                        ),
+                        $statusCode,
+                        $response->getHeaders(),
+                        (string) $response->getBody()
+                    );
+                }
+            );
+    }
+
+    /**
+     * Create request for operation 'testsPathStringPathStringIntegerPathInteger'
+     *
+     * @param  string $path_string (required)
+     * @param  int $path_integer (required)
+     * @param  string $contentType The value for the Content-Type header. Check self::contentTypes['testsPathStringPathStringIntegerPathInteger'] to see the possible values for this operation
+     *
+     * @throws \InvalidArgumentException
+     * @return \GuzzleHttp\Psr7\Request
+     */
+    public function testsPathStringPathStringIntegerPathIntegerRequest($path_string, $path_integer, string $contentType = self::contentTypes['testsPathStringPathStringIntegerPathInteger'][0])
+    {
+
+        // verify the required parameter 'path_string' is set
+        if ($path_string === null || (is_array($path_string) && count($path_string) === 0)) {
+            throw new \InvalidArgumentException(
+                'Missing the required parameter $path_string when calling testsPathStringPathStringIntegerPathInteger'
+            );
+        }
+
+        // verify the required parameter 'path_integer' is set
+        if ($path_integer === null || (is_array($path_integer) && count($path_integer) === 0)) {
+            throw new \InvalidArgumentException(
+                'Missing the required parameter $path_integer when calling testsPathStringPathStringIntegerPathInteger'
+            );
+        }
+
+
+        $resourcePath = '/path/string/{path_string}/integer/{path_integer}';
+        $formParams = [];
+        $queryParams = [];
+        $headerParams = [];
+        $httpBody = '';
+        $multipart = false;
+
+
+
+        // path params
+        if ($path_string !== null) {
+            $resourcePath = str_replace(
+                '{' . 'path_string' . '}',
+                ObjectSerializer::toPathValue($path_string),
+                $resourcePath
+            );
+        }
+        // path params
+        if ($path_integer !== null) {
+            $resourcePath = str_replace(
+                '{' . 'path_integer' . '}',
+                ObjectSerializer::toPathValue($path_integer),
+                $resourcePath
+            );
+        }
+
+
+        $headers = $this->headerSelector->selectHeaders(
+            ['text/plain', ],
+            $contentType,
+            $multipart
+        );
+
+        // for model (json/xml)
+        if (count($formParams) > 0) {
+            if ($multipart) {
+                $multipartContents = [];
+                foreach ($formParams as $formParamName => $formParamValue) {
+                    $formParamValueItems = is_array($formParamValue) ? $formParamValue : [$formParamValue];
+                    foreach ($formParamValueItems as $formParamValueItem) {
+                        $multipartContents[] = [
+                            'name' => $formParamName,
+                            'contents' => $formParamValueItem
+                        ];
+                    }
+                }
+                // for HTTP post (form)
+                $httpBody = new MultipartStream($multipartContents);
+
+            } elseif (stripos($headers['Content-Type'], 'application/json') !== false) {
+                # if Content-Type contains "application/json", json_encode the form parameters
+                $httpBody = \GuzzleHttp\Utils::jsonEncode($formParams);
+            } else {
+                // for HTTP post (form)
+                $httpBody = ObjectSerializer::buildQuery($formParams);
+            }
+        }
+
+
+        $defaultHeaders = [];
+        if ($this->config->getUserAgent()) {
+            $defaultHeaders['User-Agent'] = $this->config->getUserAgent();
+        }
+
+        $headers = array_merge(
+            $defaultHeaders,
+            $headerParams,
+            $headers
+        );
+
+        $operationHost = $this->config->getHost();
+        $query = ObjectSerializer::buildQuery($queryParams);
+        return new Request(
+            'GET',
+            $operationHost . $resourcePath . ($query ? "?{$query}" : ''),
+            $headers,
+            $httpBody
+        );
+    }
+
+    /**
+     * Create http client option
+     *
+     * @throws \RuntimeException on file opening failure
+     * @return array of http client options
+     */
+    protected function createHttpClientOption()
+    {
+        $options = [];
+        if ($this->config->getDebug()) {
+            $options[RequestOptions::DEBUG] = fopen($this->config->getDebugFile(), 'a');
+            if (!$options[RequestOptions::DEBUG]) {
+                throw new \RuntimeException('Failed to open the debug file: ' . $this->config->getDebugFile());
+            }
+        }
+
+        return $options;
+    }
+}

samples/client/echo_api/php-nextgen/src/ApiException.php

@@ -0,0 +1,120 @@
+<?php
+/**
+ * ApiException
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client;
+
+use \Exception;
+
+/**
+ * ApiException Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+class ApiException extends Exception
+{
+    /**
+     * The HTTP body of the server response either as Json or string.
+     *
+     * @var \stdClass|string|null
+     */
+    protected $responseBody;
+
+    /**
+     * The HTTP header of the server response.
+     *
+     * @var string[]|null
+     */
+    protected $responseHeaders;
+
+    /**
+     * The deserialized response object
+     *
+     * @var \stdClass|string|null
+     */
+    protected $responseObject;
+
+    /**
+     * Constructor
+     *
+     * @param string                $message         Error message
+     * @param int                   $code            HTTP status code
+     * @param string[]|null         $responseHeaders HTTP response header
+     * @param \stdClass|string|null $responseBody    HTTP decoded body of the server response either as \stdClass or string
+     */
+    public function __construct($message = "", $code = 0, $responseHeaders = [], $responseBody = null)
+    {
+        parent::__construct($message, $code);
+        $this->responseHeaders = $responseHeaders;
+        $this->responseBody = $responseBody;
+    }
+
+    /**
+     * Gets the HTTP response header
+     *
+     * @return string[]|null HTTP response header
+     */
+    public function getResponseHeaders()
+    {
+        return $this->responseHeaders;
+    }
+
+    /**
+     * Gets the HTTP body of the server response either as Json or string
+     *
+     * @return \stdClass|string|null HTTP body of the server response either as \stdClass or string
+     */
+    public function getResponseBody()
+    {
+        return $this->responseBody;
+    }
+
+    /**
+     * Sets the deserialized response object (during deserialization)
+     *
+     * @param mixed $obj Deserialized response object
+     *
+     * @return void
+     */
+    public function setResponseObject($obj)
+    {
+        $this->responseObject = $obj;
+    }
+
+    /**
+     * Gets the deserialized response object (during deserialization)
+     *
+     * @return mixed the deserialized response object
+     */
+    public function getResponseObject()
+    {
+        return $this->responseObject;
+    }
+}

samples/client/echo_api/php-nextgen/src/Configuration.php

@@ -0,0 +1,531 @@
+<?php
+/**
+ * Configuration
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client;
+
+/**
+ * Configuration Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+class Configuration
+{
+    public const BOOLEAN_FORMAT_INT = 'int';
+    public const BOOLEAN_FORMAT_STRING = 'string';
+
+    /**
+     * @var Configuration
+     */
+    private static $defaultConfiguration;
+
+    /**
+     * Associate array to store API key(s)
+     *
+     * @var string[]
+     */
+    protected $apiKeys = [];
+
+    /**
+     * Associate array to store API prefix (e.g. Bearer)
+     *
+     * @var string[]
+     */
+    protected $apiKeyPrefixes = [];
+
+    /**
+     * Access token for OAuth/Bearer authentication
+     *
+     * @var string
+     */
+    protected $accessToken = '';
+
+    /**
+     * Boolean format for query string
+     *
+     * @var string
+     */
+    protected $booleanFormatForQueryString = self::BOOLEAN_FORMAT_INT;
+
+    /**
+     * Username for HTTP basic authentication
+     *
+     * @var string
+     */
+    protected $username = '';
+
+    /**
+     * Password for HTTP basic authentication
+     *
+     * @var string
+     */
+    protected $password = '';
+
+    /**
+     * The host
+     *
+     * @var string
+     */
+    protected $host = 'http://localhost:3000';
+
+    /**
+     * User agent of the HTTP request, set to "OpenAPI-Generator/{version}/PHP" by default
+     *
+     * @var string
+     */
+    protected $userAgent = 'OpenAPI-Generator/1.0.0/PHP';
+
+    /**
+     * Debug switch (default set to false)
+     *
+     * @var bool
+     */
+    protected $debug = false;
+
+    /**
+     * Debug file location (log to STDOUT by default)
+     *
+     * @var string
+     */
+    protected $debugFile = 'php://output';
+
+    /**
+     * Debug file location (log to STDOUT by default)
+     *
+     * @var string
+     */
+    protected $tempFolderPath;
+
+    /**
+     * Constructor
+     */
+    public function __construct()
+    {
+        $this->tempFolderPath = sys_get_temp_dir();
+    }
+
+    /**
+     * Sets API key
+     *
+     * @param string $apiKeyIdentifier API key identifier (authentication scheme)
+     * @param string $key              API key or token
+     *
+     * @return $this
+     */
+    public function setApiKey($apiKeyIdentifier, $key)
+    {
+        $this->apiKeys[$apiKeyIdentifier] = $key;
+        return $this;
+    }
+
+    /**
+     * Gets API key
+     *
+     * @param string $apiKeyIdentifier API key identifier (authentication scheme)
+     *
+     * @return null|string API key or token
+     */
+    public function getApiKey($apiKeyIdentifier)
+    {
+        return isset($this->apiKeys[$apiKeyIdentifier]) ? $this->apiKeys[$apiKeyIdentifier] : null;
+    }
+
+    /**
+     * Sets the prefix for API key (e.g. Bearer)
+     *
+     * @param string $apiKeyIdentifier API key identifier (authentication scheme)
+     * @param string $prefix           API key prefix, e.g. Bearer
+     *
+     * @return $this
+     */
+    public function setApiKeyPrefix($apiKeyIdentifier, $prefix)
+    {
+        $this->apiKeyPrefixes[$apiKeyIdentifier] = $prefix;
+        return $this;
+    }
+
+    /**
+     * Gets API key prefix
+     *
+     * @param string $apiKeyIdentifier API key identifier (authentication scheme)
+     *
+     * @return null|string
+     */
+    public function getApiKeyPrefix($apiKeyIdentifier)
+    {
+        return isset($this->apiKeyPrefixes[$apiKeyIdentifier]) ? $this->apiKeyPrefixes[$apiKeyIdentifier] : null;
+    }
+
+    /**
+     * Sets the access token for OAuth
+     *
+     * @param string $accessToken Token for OAuth
+     *
+     * @return $this
+     */
+    public function setAccessToken($accessToken)
+    {
+        $this->accessToken = $accessToken;
+        return $this;
+    }
+
+    /**
+     * Gets the access token for OAuth
+     *
+     * @return string Access token for OAuth
+     */
+    public function getAccessToken()
+    {
+        return $this->accessToken;
+    }
+
+    /**
+     * Sets boolean format for query string.
+     *
+     * @param string $booleanFormatForQueryString Boolean format for query string
+     *
+     * @return $this
+     */
+    public function setBooleanFormatForQueryString(string $booleanFormat)
+    {
+        $this->booleanFormatForQueryString = $booleanFormat;
+
+        return $this;
+    }
+
+    /**
+     * Gets boolean format for query string.
+     *
+     * @return string Boolean format for query string
+     */
+    public function getBooleanFormatForQueryString(): string
+    {
+        return $this->booleanFormatForQueryString;
+    }
+
+    /**
+     * Sets the username for HTTP basic authentication
+     *
+     * @param string $username Username for HTTP basic authentication
+     *
+     * @return $this
+     */
+    public function setUsername($username)
+    {
+        $this->username = $username;
+        return $this;
+    }
+
+    /**
+     * Gets the username for HTTP basic authentication
+     *
+     * @return string Username for HTTP basic authentication
+     */
+    public function getUsername()
+    {
+        return $this->username;
+    }
+
+    /**
+     * Sets the password for HTTP basic authentication
+     *
+     * @param string $password Password for HTTP basic authentication
+     *
+     * @return $this
+     */
+    public function setPassword($password)
+    {
+        $this->password = $password;
+        return $this;
+    }
+
+    /**
+     * Gets the password for HTTP basic authentication
+     *
+     * @return string Password for HTTP basic authentication
+     */
+    public function getPassword()
+    {
+        return $this->password;
+    }
+
+    /**
+     * Sets the host
+     *
+     * @param string $host Host
+     *
+     * @return $this
+     */
+    public function setHost($host)
+    {
+        $this->host = $host;
+        return $this;
+    }
+
+    /**
+     * Gets the host
+     *
+     * @return string Host
+     */
+    public function getHost()
+    {
+        return $this->host;
+    }
+
+    /**
+     * Sets the user agent of the api client
+     *
+     * @param string $userAgent the user agent of the api client
+     *
+     * @throws \InvalidArgumentException
+     * @return $this
+     */
+    public function setUserAgent($userAgent)
+    {
+        if (!is_string($userAgent)) {
+            throw new \InvalidArgumentException('User-agent must be a string.');
+        }
+
+        $this->userAgent = $userAgent;
+        return $this;
+    }
+
+    /**
+     * Gets the user agent of the api client
+     *
+     * @return string user agent
+     */
+    public function getUserAgent()
+    {
+        return $this->userAgent;
+    }
+
+    /**
+     * Sets debug flag
+     *
+     * @param bool $debug Debug flag
+     *
+     * @return $this
+     */
+    public function setDebug($debug)
+    {
+        $this->debug = $debug;
+        return $this;
+    }
+
+    /**
+     * Gets the debug flag
+     *
+     * @return bool
+     */
+    public function getDebug()
+    {
+        return $this->debug;
+    }
+
+    /**
+     * Sets the debug file
+     *
+     * @param string $debugFile Debug file
+     *
+     * @return $this
+     */
+    public function setDebugFile($debugFile)
+    {
+        $this->debugFile = $debugFile;
+        return $this;
+    }
+
+    /**
+     * Gets the debug file
+     *
+     * @return string
+     */
+    public function getDebugFile()
+    {
+        return $this->debugFile;
+    }
+
+    /**
+     * Sets the temp folder path
+     *
+     * @param string $tempFolderPath Temp folder path
+     *
+     * @return $this
+     */
+    public function setTempFolderPath($tempFolderPath)
+    {
+        $this->tempFolderPath = $tempFolderPath;
+        return $this;
+    }
+
+    /**
+     * Gets the temp folder path
+     *
+     * @return string Temp folder path
+     */
+    public function getTempFolderPath()
+    {
+        return $this->tempFolderPath;
+    }
+
+    /**
+     * Gets the default configuration instance
+     *
+     * @return Configuration
+     */
+    public static function getDefaultConfiguration()
+    {
+        if (self::$defaultConfiguration === null) {
+            self::$defaultConfiguration = new Configuration();
+        }
+
+        return self::$defaultConfiguration;
+    }
+
+    /**
+     * Sets the default configuration instance
+     *
+     * @param Configuration $config An instance of the Configuration Object
+     *
+     * @return void
+     */
+    public static function setDefaultConfiguration(Configuration $config)
+    {
+        self::$defaultConfiguration = $config;
+    }
+
+    /**
+     * Gets the essential information for debugging
+     *
+     * @return string The report for debugging
+     */
+    public static function toDebugReport()
+    {
+        $report  = 'PHP SDK (OpenAPI\Client) Debug Report:' . PHP_EOL;
+        $report .= '    OS: ' . php_uname() . PHP_EOL;
+        $report .= '    PHP Version: ' . PHP_VERSION . PHP_EOL;
+        $report .= '    The version of the OpenAPI document: 0.1.0' . PHP_EOL;
+        $report .= '    Temp Folder Path: ' . self::getDefaultConfiguration()->getTempFolderPath() . PHP_EOL;
+
+        return $report;
+    }
+
+    /**
+     * Get API key (with prefix if set)
+     *
+     * @param  string $apiKeyIdentifier name of apikey
+     *
+     * @return null|string API key with the prefix
+     */
+    public function getApiKeyWithPrefix($apiKeyIdentifier)
+    {
+        $prefix = $this->getApiKeyPrefix($apiKeyIdentifier);
+        $apiKey = $this->getApiKey($apiKeyIdentifier);
+
+        if ($apiKey === null) {
+            return null;
+        }
+
+        if ($prefix === null) {
+            $keyWithPrefix = $apiKey;
+        } else {
+            $keyWithPrefix = $prefix . ' ' . $apiKey;
+        }
+
+        return $keyWithPrefix;
+    }
+
+    /**
+     * Returns an array of host settings
+     *
+     * @return array an array of host settings
+     */
+    public function getHostSettings()
+    {
+        return [
+            [
+                "url" => "http://localhost:3000",
+                "description" => "No description provided",
+            ]
+        ];
+    }
+
+    /**
+    * Returns URL based on host settings, index and variables
+    *
+    * @param array      $hostSettings array of host settings, generated from getHostSettings() or equivalent from the API clients
+    * @param int        $hostIndex    index of the host settings
+    * @param array|null $variables    hash of variable and the corresponding value (optional)
+    * @return string URL based on host settings
+    */
+    public static function getHostString(array $hostsSettings, $hostIndex, array $variables = null)
+    {
+        if (null === $variables) {
+            $variables = [];
+        }
+
+        // check array index out of bound
+        if ($hostIndex < 0 || $hostIndex >= count($hostsSettings)) {
+            throw new \InvalidArgumentException("Invalid index $hostIndex when selecting the host. Must be less than ".count($hostsSettings));
+        }
+
+        $host = $hostsSettings[$hostIndex];
+        $url = $host["url"];
+
+        // go through variable and assign a value
+        foreach ($host["variables"] ?? [] as $name => $variable) {
+            if (array_key_exists($name, $variables)) { // check to see if it's in the variables provided by the user
+                if (!isset($variable['enum_values']) || in_array($variables[$name], $variable["enum_values"], true)) { // check to see if the value is in the enum
+                    $url = str_replace("{".$name."}", $variables[$name], $url);
+                } else {
+                    throw new \InvalidArgumentException("The variable `$name` in the host URL has invalid value ".$variables[$name].". Must be ".join(',', $variable["enum_values"]).".");
+                }
+            } else {
+                // use default value
+                $url = str_replace("{".$name."}", $variable["default_value"], $url);
+            }
+        }
+
+        return $url;
+    }
+
+    /**
+     * Returns URL based on the index and variables
+     *
+     * @param int        $index     index of the host settings
+     * @param array|null $variables hash of variable and the corresponding value (optional)
+     * @return string URL based on host settings
+     */
+    public function getHostFromSettings($index, $variables = null)
+    {
+        return self::getHostString($this->getHostSettings(), $index, $variables);
+    }
+}

samples/client/echo_api/php-nextgen/src/HeaderSelector.php

@@ -0,0 +1,246 @@
+<?php
+/**
+ * HeaderSelector
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client;
+
+/**
+ * HeaderSelector Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+class HeaderSelector
+{
+    /**
+     * @param string[] $accept
+     * @param string   $contentType
+     * @param bool     $isMultipart
+     * @return string[]
+     */
+    public function selectHeaders(array $accept, string $contentType, bool $isMultipart): array
+    {
+        $headers = [];
+
+        $accept = $this->selectAcceptHeader($accept);
+        if ($accept !== null) {
+            $headers['Accept'] = $accept;
+        }
+
+        if (!$isMultipart) {
+            if($contentType === '') {
+                $contentType = 'application/json';
+            }
+
+            $headers['Content-Type'] = $contentType;
+        }
+
+        return $headers;
+    }
+
+    /**
+     * Return the header 'Accept' based on an array of Accept provided.
+     *
+     * @param string[] $accept Array of header
+     *
+     * @return null|string Accept (e.g. application/json)
+     */
+    private function selectAcceptHeader(array $accept): ?string
+    {
+        # filter out empty entries
+        $accept = array_filter($accept);
+
+        if (count($accept) === 0) {
+            return null;
+        }
+
+        # If there's only one Accept header, just use it
+        if (count($accept) === 1) {
+            return reset($accept);
+        }
+
+        # If none of the available Accept headers is of type "json", then just use all them
+        $headersWithJson = preg_grep('~(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$~', $accept);
+        if (count($headersWithJson) === 0) {
+            return implode(',', $accept);
+        }
+
+        # If we got here, then we need add quality values (weight), as described in IETF RFC 9110, Items 12.4.2/12.5.1,
+        # to give the highest priority to json-like headers - recalculating the existing ones, if needed
+        return $this->getAcceptHeaderWithAdjustedWeight($accept, $headersWithJson);
+    }
+
+    /**
+    * Create an Accept header string from the given "Accept" headers array, recalculating all weights
+    *
+    * @param string[] $accept            Array of Accept Headers
+    * @param string[] $headersWithJson   Array of Accept Headers of type "json"
+    *
+    * @return string "Accept" Header (e.g. "application/json, text/html; q=0.9")
+    */
+    private function getAcceptHeaderWithAdjustedWeight(array $accept, array $headersWithJson): string
+    {
+        $processedHeaders = [
+            'withApplicationJson' => [],
+            'withJson' => [],
+            'withoutJson' => [],
+        ];
+
+        foreach ($accept as $header) {
+
+            $headerData = $this->getHeaderAndWeight($header);
+
+            if (stripos($headerData['header'], 'application/json') === 0) {
+                $processedHeaders['withApplicationJson'][] = $headerData;
+            } elseif (in_array($header, $headersWithJson, true)) {
+                $processedHeaders['withJson'][] = $headerData;
+            } else {
+                $processedHeaders['withoutJson'][] = $headerData;
+            }
+        }
+
+        $acceptHeaders = [];
+        $currentWeight = 1000;
+
+        $hasMoreThan28Headers = count($accept) > 28;
+
+        foreach($processedHeaders as $headers) {
+            if (count($headers) > 0) {
+                $acceptHeaders[] = $this->adjustWeight($headers, $currentWeight, $hasMoreThan28Headers);
+            }
+        }
+
+        $acceptHeaders = array_merge(...$acceptHeaders);
+
+        return implode(',', $acceptHeaders);
+    }
+
+    /**
+     * Given an Accept header, returns an associative array splitting the header and its weight
+     *
+     * @param string $header "Accept" Header
+     *
+     * @return array with the header and its weight
+     */
+    private function getHeaderAndWeight(string $header): array
+    {
+        # matches headers with weight, splitting the header and the weight in $outputArray
+        if (preg_match('/(.*);\s*q=(1(?:\.0+)?|0\.\d+)$/', $header, $outputArray) === 1) {
+            $headerData = [
+                'header' => $outputArray[1],
+                'weight' => (int)($outputArray[2] * 1000),
+            ];
+        } else {
+            $headerData = [
+                'header' => trim($header),
+                'weight' => 1000,
+            ];
+        }
+
+        return $headerData;
+    }
+
+    /**
+     * @param array[] $headers
+     * @param float   $currentWeight
+     * @param bool    $hasMoreThan28Headers
+     * @return string[] array of adjusted "Accept" headers
+     */
+    private function adjustWeight(array $headers, float &$currentWeight, bool $hasMoreThan28Headers): array
+    {
+        usort($headers, function (array $a, array $b) {
+            return $b['weight'] - $a['weight'];
+        });
+
+        $acceptHeaders = [];
+        foreach ($headers as $index => $header) {
+            if($index > 0 && $headers[$index - 1]['weight'] > $header['weight'])
+            {
+                $currentWeight = $this->getNextWeight($currentWeight, $hasMoreThan28Headers);
+            }
+
+            $weight = $currentWeight;
+
+            $acceptHeaders[] = $this->buildAcceptHeader($header['header'], $weight);
+        }
+
+        $currentWeight = $this->getNextWeight($currentWeight, $hasMoreThan28Headers);
+
+        return $acceptHeaders;
+    }
+
+    /**
+     * @param string $header
+     * @param int    $weight
+     * @return string
+     */
+    private function buildAcceptHeader(string $header, int $weight): string
+    {
+        if($weight === 1000) {
+            return $header;
+        }
+
+        return trim($header, '; ') . ';q=' . rtrim(sprintf('%0.3f', $weight / 1000), '0');
+    }
+
+    /**
+     * Calculate the next weight, based on the current one.
+     *
+     * If there are less than 28 "Accept" headers, the weights will be decreased by 1 on its highest significant digit, using the
+     * following formula:
+     *
+     *    next weight = current weight - 10 ^ (floor(log(current weight - 1)))
+     *
+     *    ( current weight minus ( 10 raised to the power of ( floor of (log to the base 10 of ( current weight minus 1 ) ) ) ) )
+     *
+     * Starting from 1000, this generates the following series:
+     *
+     * 1000, 900, 800, 700, 600, 500, 400, 300, 200, 100, 90, 80, 70, 60, 50, 40, 30, 20, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1
+     *
+     * The resulting quality codes are closer to the average "normal" usage of them (like "q=0.9", "q=0.8" and so on), but it only works
+     * if there is a maximum of 28 "Accept" headers. If we have more than that (which is extremely unlikely), then we fall back to a 1-by-1
+     * decrement rule, which will result in quality codes like "q=0.999", "q=0.998" etc.
+     *
+     * @param int  $currentWeight varying from 1 to 1000 (will be divided by 1000 to build the quality value)
+     * @param bool $hasMoreThan28Headers
+     * @return int
+     */
+    public function getNextWeight(int $currentWeight, bool $hasMoreThan28Headers): int
+    {
+        if ($currentWeight <= 1) {
+            return 1;
+        }
+
+        if ($hasMoreThan28Headers) {
+            return $currentWeight - 1;
+        }
+
+        return $currentWeight - 10 ** floor( log10($currentWeight - 1) );
+    }
+}

samples/client/echo_api/php-nextgen/src/Model/Bird.php

@@ -0,0 +1,444 @@
+<?php
+/**
+ * Bird
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client\Model;
+
+use \ArrayAccess;
+use \OpenAPI\Client\ObjectSerializer;
+
+/**
+ * Bird Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ * @implements \ArrayAccess<string, mixed>
+ */
+class Bird implements ModelInterface, ArrayAccess, \JsonSerializable
+{
+    public const DISCRIMINATOR = null;
+
+    /**
+      * The original name of the model.
+      *
+      * @var string
+      */
+    protected static $openAPIModelName = 'Bird';
+
+    /**
+      * Array of property to type mappings. Used for (de)serialization
+      *
+      * @var string[]
+      */
+    protected static $openAPITypes = [
+        'size' => 'string',
+        'color' => 'string'
+    ];
+
+    /**
+      * Array of property to format mappings. Used for (de)serialization
+      *
+      * @var string[]
+      * @phpstan-var array<string, string|null>
+      * @psalm-var array<string, string|null>
+      */
+    protected static $openAPIFormats = [
+        'size' => null,
+        'color' => null
+    ];
+
+    /**
+      * Array of nullable properties. Used for (de)serialization
+      *
+      * @var boolean[]
+      */
+    protected static array $openAPINullables = [
+        'size' => false,
+		'color' => false
+    ];
+
+    /**
+      * If a nullable field gets set to null, insert it here
+      *
+      * @var boolean[]
+      */
+    protected array $openAPINullablesSetToNull = [];
+
+    /**
+     * Array of property to type mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPITypes()
+    {
+        return self::$openAPITypes;
+    }
+
+    /**
+     * Array of property to format mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPIFormats()
+    {
+        return self::$openAPIFormats;
+    }
+
+    /**
+     * Array of nullable properties
+     *
+     * @return array
+     */
+    protected static function openAPINullables(): array
+    {
+        return self::$openAPINullables;
+    }
+
+    /**
+     * Array of nullable field names deliberately set to null
+     *
+     * @return boolean[]
+     */
+    private function getOpenAPINullablesSetToNull(): array
+    {
+        return $this->openAPINullablesSetToNull;
+    }
+
+    /**
+     * Setter - Array of nullable field names deliberately set to null
+     *
+     * @param boolean[] $openAPINullablesSetToNull
+     */
+    private function setOpenAPINullablesSetToNull(array $openAPINullablesSetToNull): void
+    {
+        $this->openAPINullablesSetToNull = $openAPINullablesSetToNull;
+    }
+
+    /**
+     * Checks if a property is nullable
+     *
+     * @param string $property
+     * @return bool
+     */
+    public static function isNullable(string $property): bool
+    {
+        return self::openAPINullables()[$property] ?? false;
+    }
+
+    /**
+     * Checks if a nullable property is set to null.
+     *
+     * @param string $property
+     * @return bool
+     */
+    public function isNullableSetToNull(string $property): bool
+    {
+        return in_array($property, $this->getOpenAPINullablesSetToNull(), true);
+    }
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @var string[]
+     */
+    protected static $attributeMap = [
+        'size' => 'size',
+        'color' => 'color'
+    ];
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @var string[]
+     */
+    protected static $setters = [
+        'size' => 'setSize',
+        'color' => 'setColor'
+    ];
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @var string[]
+     */
+    protected static $getters = [
+        'size' => 'getSize',
+        'color' => 'getColor'
+    ];
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @return array
+     */
+    public static function attributeMap()
+    {
+        return self::$attributeMap;
+    }
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @return array
+     */
+    public static function setters()
+    {
+        return self::$setters;
+    }
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @return array
+     */
+    public static function getters()
+    {
+        return self::$getters;
+    }
+
+    /**
+     * The original name of the model.
+     *
+     * @return string
+     */
+    public function getModelName()
+    {
+        return self::$openAPIModelName;
+    }
+
+
+    /**
+     * Associative array for storing property values
+     *
+     * @var mixed[]
+     */
+    protected $container = [];
+
+    /**
+     * Constructor
+     *
+     * @param mixed[] $data Associated array of property values
+     *                      initializing the model
+     */
+    public function __construct(array $data = null)
+    {
+        $this->setIfExists('size', $data ?? [], null);
+        $this->setIfExists('color', $data ?? [], null);
+    }
+
+    /**
+    * Sets $this->container[$variableName] to the given data or to the given default Value; if $variableName
+    * is nullable and its value is set to null in the $fields array, then mark it as "set to null" in the
+    * $this->openAPINullablesSetToNull array
+    *
+    * @param string $variableName
+    * @param array  $fields
+    * @param mixed  $defaultValue
+    */
+    private function setIfExists(string $variableName, array $fields, $defaultValue): void
+    {
+        if (self::isNullable($variableName) && array_key_exists($variableName, $fields) && is_null($fields[$variableName])) {
+            $this->openAPINullablesSetToNull[] = $variableName;
+        }
+
+        $this->container[$variableName] = $fields[$variableName] ?? $defaultValue;
+    }
+
+    /**
+     * Show all the invalid properties with reasons.
+     *
+     * @return array invalid properties with reasons
+     */
+    public function listInvalidProperties()
+    {
+        $invalidProperties = [];
+
+        return $invalidProperties;
+    }
+
+    /**
+     * Validate all the properties in the model
+     * return true if all passed
+     *
+     * @return bool True if all properties are valid
+     */
+    public function valid()
+    {
+        return count($this->listInvalidProperties()) === 0;
+    }
+
+
+    /**
+     * Gets size
+     *
+     * @return string|null
+     */
+    public function getSize()
+    {
+        return $this->container['size'];
+    }
+
+    /**
+     * Sets size
+     *
+     * @param string|null $size size
+     *
+     * @return self
+     */
+    public function setSize($size)
+    {
+        if (is_null($size)) {
+            throw new \InvalidArgumentException('non-nullable size cannot be null');
+        }
+        $this->container['size'] = $size;
+
+        return $this;
+    }
+
+    /**
+     * Gets color
+     *
+     * @return string|null
+     */
+    public function getColor()
+    {
+        return $this->container['color'];
+    }
+
+    /**
+     * Sets color
+     *
+     * @param string|null $color color
+     *
+     * @return self
+     */
+    public function setColor($color)
+    {
+        if (is_null($color)) {
+            throw new \InvalidArgumentException('non-nullable color cannot be null');
+        }
+        $this->container['color'] = $color;
+
+        return $this;
+    }
+    /**
+     * Returns true if offset exists. False otherwise.
+     *
+     * @param integer $offset Offset
+     *
+     * @return boolean
+     */
+    public function offsetExists($offset): bool
+    {
+        return isset($this->container[$offset]);
+    }
+
+    /**
+     * Gets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return mixed|null
+     */
+    #[\ReturnTypeWillChange]
+    public function offsetGet($offset)
+    {
+        return $this->container[$offset] ?? null;
+    }
+
+    /**
+     * Sets value based on offset.
+     *
+     * @param int|null $offset Offset
+     * @param mixed    $value  Value to be set
+     *
+     * @return void
+     */
+    public function offsetSet($offset, $value): void
+    {
+        if (is_null($offset)) {
+            $this->container[] = $value;
+        } else {
+            $this->container[$offset] = $value;
+        }
+    }
+
+    /**
+     * Unsets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return void
+     */
+    public function offsetUnset($offset): void
+    {
+        unset($this->container[$offset]);
+    }
+
+    /**
+     * Serializes the object to a value that can be serialized natively by json_encode().
+     * @link https://www.php.net/manual/en/jsonserializable.jsonserialize.php
+     *
+     * @return mixed Returns data which can be serialized by json_encode(), which is a value
+     * of any type other than a resource.
+     */
+    #[\ReturnTypeWillChange]
+    public function jsonSerialize()
+    {
+       return ObjectSerializer::sanitizeForSerialization($this);
+    }
+
+    /**
+     * Gets the string presentation of the object
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return json_encode(
+            ObjectSerializer::sanitizeForSerialization($this),
+            JSON_PRETTY_PRINT
+        );
+    }
+
+    /**
+     * Gets a header-safe presentation of the object
+     *
+     * @return string
+     */
+    public function toHeaderValue()
+    {
+        return json_encode(ObjectSerializer::sanitizeForSerialization($this));
+    }
+}
+
+

samples/client/echo_api/php-nextgen/src/Model/Category.php

@@ -0,0 +1,444 @@
+<?php
+/**
+ * Category
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client\Model;
+
+use \ArrayAccess;
+use \OpenAPI\Client\ObjectSerializer;
+
+/**
+ * Category Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ * @implements \ArrayAccess<string, mixed>
+ */
+class Category implements ModelInterface, ArrayAccess, \JsonSerializable
+{
+    public const DISCRIMINATOR = null;
+
+    /**
+      * The original name of the model.
+      *
+      * @var string
+      */
+    protected static $openAPIModelName = 'Category';
+
+    /**
+      * Array of property to type mappings. Used for (de)serialization
+      *
+      * @var string[]
+      */
+    protected static $openAPITypes = [
+        'id' => 'int',
+        'name' => 'string'
+    ];
+
+    /**
+      * Array of property to format mappings. Used for (de)serialization
+      *
+      * @var string[]
+      * @phpstan-var array<string, string|null>
+      * @psalm-var array<string, string|null>
+      */
+    protected static $openAPIFormats = [
+        'id' => 'int64',
+        'name' => null
+    ];
+
+    /**
+      * Array of nullable properties. Used for (de)serialization
+      *
+      * @var boolean[]
+      */
+    protected static array $openAPINullables = [
+        'id' => false,
+		'name' => false
+    ];
+
+    /**
+      * If a nullable field gets set to null, insert it here
+      *
+      * @var boolean[]
+      */
+    protected array $openAPINullablesSetToNull = [];
+
+    /**
+     * Array of property to type mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPITypes()
+    {
+        return self::$openAPITypes;
+    }
+
+    /**
+     * Array of property to format mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPIFormats()
+    {
+        return self::$openAPIFormats;
+    }
+
+    /**
+     * Array of nullable properties
+     *
+     * @return array
+     */
+    protected static function openAPINullables(): array
+    {
+        return self::$openAPINullables;
+    }
+
+    /**
+     * Array of nullable field names deliberately set to null
+     *
+     * @return boolean[]
+     */
+    private function getOpenAPINullablesSetToNull(): array
+    {
+        return $this->openAPINullablesSetToNull;
+    }
+
+    /**
+     * Setter - Array of nullable field names deliberately set to null
+     *
+     * @param boolean[] $openAPINullablesSetToNull
+     */
+    private function setOpenAPINullablesSetToNull(array $openAPINullablesSetToNull): void
+    {
+        $this->openAPINullablesSetToNull = $openAPINullablesSetToNull;
+    }
+
+    /**
+     * Checks if a property is nullable
+     *
+     * @param string $property
+     * @return bool
+     */
+    public static function isNullable(string $property): bool
+    {
+        return self::openAPINullables()[$property] ?? false;
+    }
+
+    /**
+     * Checks if a nullable property is set to null.
+     *
+     * @param string $property
+     * @return bool
+     */
+    public function isNullableSetToNull(string $property): bool
+    {
+        return in_array($property, $this->getOpenAPINullablesSetToNull(), true);
+    }
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @var string[]
+     */
+    protected static $attributeMap = [
+        'id' => 'id',
+        'name' => 'name'
+    ];
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @var string[]
+     */
+    protected static $setters = [
+        'id' => 'setId',
+        'name' => 'setName'
+    ];
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @var string[]
+     */
+    protected static $getters = [
+        'id' => 'getId',
+        'name' => 'getName'
+    ];
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @return array
+     */
+    public static function attributeMap()
+    {
+        return self::$attributeMap;
+    }
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @return array
+     */
+    public static function setters()
+    {
+        return self::$setters;
+    }
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @return array
+     */
+    public static function getters()
+    {
+        return self::$getters;
+    }
+
+    /**
+     * The original name of the model.
+     *
+     * @return string
+     */
+    public function getModelName()
+    {
+        return self::$openAPIModelName;
+    }
+
+
+    /**
+     * Associative array for storing property values
+     *
+     * @var mixed[]
+     */
+    protected $container = [];
+
+    /**
+     * Constructor
+     *
+     * @param mixed[] $data Associated array of property values
+     *                      initializing the model
+     */
+    public function __construct(array $data = null)
+    {
+        $this->setIfExists('id', $data ?? [], null);
+        $this->setIfExists('name', $data ?? [], null);
+    }
+
+    /**
+    * Sets $this->container[$variableName] to the given data or to the given default Value; if $variableName
+    * is nullable and its value is set to null in the $fields array, then mark it as "set to null" in the
+    * $this->openAPINullablesSetToNull array
+    *
+    * @param string $variableName
+    * @param array  $fields
+    * @param mixed  $defaultValue
+    */
+    private function setIfExists(string $variableName, array $fields, $defaultValue): void
+    {
+        if (self::isNullable($variableName) && array_key_exists($variableName, $fields) && is_null($fields[$variableName])) {
+            $this->openAPINullablesSetToNull[] = $variableName;
+        }
+
+        $this->container[$variableName] = $fields[$variableName] ?? $defaultValue;
+    }
+
+    /**
+     * Show all the invalid properties with reasons.
+     *
+     * @return array invalid properties with reasons
+     */
+    public function listInvalidProperties()
+    {
+        $invalidProperties = [];
+
+        return $invalidProperties;
+    }
+
+    /**
+     * Validate all the properties in the model
+     * return true if all passed
+     *
+     * @return bool True if all properties are valid
+     */
+    public function valid()
+    {
+        return count($this->listInvalidProperties()) === 0;
+    }
+
+
+    /**
+     * Gets id
+     *
+     * @return int|null
+     */
+    public function getId()
+    {
+        return $this->container['id'];
+    }
+
+    /**
+     * Sets id
+     *
+     * @param int|null $id id
+     *
+     * @return self
+     */
+    public function setId($id)
+    {
+        if (is_null($id)) {
+            throw new \InvalidArgumentException('non-nullable id cannot be null');
+        }
+        $this->container['id'] = $id;
+
+        return $this;
+    }
+
+    /**
+     * Gets name
+     *
+     * @return string|null
+     */
+    public function getName()
+    {
+        return $this->container['name'];
+    }
+
+    /**
+     * Sets name
+     *
+     * @param string|null $name name
+     *
+     * @return self
+     */
+    public function setName($name)
+    {
+        if (is_null($name)) {
+            throw new \InvalidArgumentException('non-nullable name cannot be null');
+        }
+        $this->container['name'] = $name;
+
+        return $this;
+    }
+    /**
+     * Returns true if offset exists. False otherwise.
+     *
+     * @param integer $offset Offset
+     *
+     * @return boolean
+     */
+    public function offsetExists($offset): bool
+    {
+        return isset($this->container[$offset]);
+    }
+
+    /**
+     * Gets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return mixed|null
+     */
+    #[\ReturnTypeWillChange]
+    public function offsetGet($offset)
+    {
+        return $this->container[$offset] ?? null;
+    }
+
+    /**
+     * Sets value based on offset.
+     *
+     * @param int|null $offset Offset
+     * @param mixed    $value  Value to be set
+     *
+     * @return void
+     */
+    public function offsetSet($offset, $value): void
+    {
+        if (is_null($offset)) {
+            $this->container[] = $value;
+        } else {
+            $this->container[$offset] = $value;
+        }
+    }
+
+    /**
+     * Unsets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return void
+     */
+    public function offsetUnset($offset): void
+    {
+        unset($this->container[$offset]);
+    }
+
+    /**
+     * Serializes the object to a value that can be serialized natively by json_encode().
+     * @link https://www.php.net/manual/en/jsonserializable.jsonserialize.php
+     *
+     * @return mixed Returns data which can be serialized by json_encode(), which is a value
+     * of any type other than a resource.
+     */
+    #[\ReturnTypeWillChange]
+    public function jsonSerialize()
+    {
+       return ObjectSerializer::sanitizeForSerialization($this);
+    }
+
+    /**
+     * Gets the string presentation of the object
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return json_encode(
+            ObjectSerializer::sanitizeForSerialization($this),
+            JSON_PRETTY_PRINT
+        );
+    }
+
+    /**
+     * Gets a header-safe presentation of the object
+     *
+     * @return string
+     */
+    public function toHeaderValue()
+    {
+        return json_encode(ObjectSerializer::sanitizeForSerialization($this));
+    }
+}
+
+

samples/client/echo_api/php-nextgen/src/Model/DataQuery.php

@@ -0,0 +1,472 @@
+<?php
+/**
+ * DataQuery
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client\Model;
+use \OpenAPI\Client\ObjectSerializer;
+
+/**
+ * DataQuery Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ * @implements \ArrayAccess<string, mixed>
+ */
+class DataQuery extends Query
+{
+    public const DISCRIMINATOR = null;
+
+    /**
+      * The original name of the model.
+      *
+      * @var string
+      */
+    protected static $openAPIModelName = 'DataQuery';
+
+    /**
+      * Array of property to type mappings. Used for (de)serialization
+      *
+      * @var string[]
+      */
+    protected static $openAPITypes = [
+        'suffix' => 'string',
+        'text' => 'string',
+        'date' => '\DateTime'
+    ];
+
+    /**
+      * Array of property to format mappings. Used for (de)serialization
+      *
+      * @var string[]
+      * @phpstan-var array<string, string|null>
+      * @psalm-var array<string, string|null>
+      */
+    protected static $openAPIFormats = [
+        'suffix' => null,
+        'text' => null,
+        'date' => 'date-time'
+    ];
+
+    /**
+      * Array of nullable properties. Used for (de)serialization
+      *
+      * @var boolean[]
+      */
+    protected static array $openAPINullables = [
+        'suffix' => false,
+		'text' => false,
+		'date' => false
+    ];
+
+    /**
+      * If a nullable field gets set to null, insert it here
+      *
+      * @var boolean[]
+      */
+    protected array $openAPINullablesSetToNull = [];
+
+    /**
+     * Array of property to type mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPITypes()
+    {
+        return self::$openAPITypes + parent::openAPITypes();
+    }
+
+    /**
+     * Array of property to format mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPIFormats()
+    {
+        return self::$openAPIFormats + parent::openAPIFormats();
+    }
+
+    /**
+     * Array of nullable properties
+     *
+     * @return array
+     */
+    protected static function openAPINullables(): array
+    {
+        return self::$openAPINullables + parent::openAPINullables();
+    }
+
+    /**
+     * Array of nullable field names deliberately set to null
+     *
+     * @return boolean[]
+     */
+    private function getOpenAPINullablesSetToNull(): array
+    {
+        return $this->openAPINullablesSetToNull;
+    }
+
+    /**
+     * Setter - Array of nullable field names deliberately set to null
+     *
+     * @param boolean[] $openAPINullablesSetToNull
+     */
+    private function setOpenAPINullablesSetToNull(array $openAPINullablesSetToNull): void
+    {
+        $this->openAPINullablesSetToNull = $openAPINullablesSetToNull;
+    }
+
+    /**
+     * Checks if a property is nullable
+     *
+     * @param string $property
+     * @return bool
+     */
+    public static function isNullable(string $property): bool
+    {
+        return self::openAPINullables()[$property] ?? false;
+    }
+
+    /**
+     * Checks if a nullable property is set to null.
+     *
+     * @param string $property
+     * @return bool
+     */
+    public function isNullableSetToNull(string $property): bool
+    {
+        return in_array($property, $this->getOpenAPINullablesSetToNull(), true);
+    }
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @var string[]
+     */
+    protected static $attributeMap = [
+        'suffix' => 'suffix',
+        'text' => 'text',
+        'date' => 'date'
+    ];
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @var string[]
+     */
+    protected static $setters = [
+        'suffix' => 'setSuffix',
+        'text' => 'setText',
+        'date' => 'setDate'
+    ];
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @var string[]
+     */
+    protected static $getters = [
+        'suffix' => 'getSuffix',
+        'text' => 'getText',
+        'date' => 'getDate'
+    ];
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @return array
+     */
+    public static function attributeMap()
+    {
+        return parent::attributeMap() + self::$attributeMap;
+    }
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @return array
+     */
+    public static function setters()
+    {
+        return parent::setters() + self::$setters;
+    }
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @return array
+     */
+    public static function getters()
+    {
+        return parent::getters() + self::$getters;
+    }
+
+    /**
+     * The original name of the model.
+     *
+     * @return string
+     */
+    public function getModelName()
+    {
+        return self::$openAPIModelName;
+    }
+
+
+
+    /**
+     * Constructor
+     *
+     * @param mixed[] $data Associated array of property values
+     *                      initializing the model
+     */
+    public function __construct(array $data = null)
+    {
+        parent::__construct($data);
+
+        $this->setIfExists('suffix', $data ?? [], null);
+        $this->setIfExists('text', $data ?? [], null);
+        $this->setIfExists('date', $data ?? [], null);
+    }
+
+    /**
+    * Sets $this->container[$variableName] to the given data or to the given default Value; if $variableName
+    * is nullable and its value is set to null in the $fields array, then mark it as "set to null" in the
+    * $this->openAPINullablesSetToNull array
+    *
+    * @param string $variableName
+    * @param array  $fields
+    * @param mixed  $defaultValue
+    */
+    private function setIfExists(string $variableName, array $fields, $defaultValue): void
+    {
+        if (self::isNullable($variableName) && array_key_exists($variableName, $fields) && is_null($fields[$variableName])) {
+            $this->openAPINullablesSetToNull[] = $variableName;
+        }
+
+        $this->container[$variableName] = $fields[$variableName] ?? $defaultValue;
+    }
+
+    /**
+     * Show all the invalid properties with reasons.
+     *
+     * @return array invalid properties with reasons
+     */
+    public function listInvalidProperties()
+    {
+        $invalidProperties = parent::listInvalidProperties();
+
+        return $invalidProperties;
+    }
+
+    /**
+     * Validate all the properties in the model
+     * return true if all passed
+     *
+     * @return bool True if all properties are valid
+     */
+    public function valid()
+    {
+        return count($this->listInvalidProperties()) === 0;
+    }
+
+
+    /**
+     * Gets suffix
+     *
+     * @return string|null
+     */
+    public function getSuffix()
+    {
+        return $this->container['suffix'];
+    }
+
+    /**
+     * Sets suffix
+     *
+     * @param string|null $suffix test suffix
+     *
+     * @return self
+     */
+    public function setSuffix($suffix)
+    {
+        if (is_null($suffix)) {
+            throw new \InvalidArgumentException('non-nullable suffix cannot be null');
+        }
+        $this->container['suffix'] = $suffix;
+
+        return $this;
+    }
+
+    /**
+     * Gets text
+     *
+     * @return string|null
+     */
+    public function getText()
+    {
+        return $this->container['text'];
+    }
+
+    /**
+     * Sets text
+     *
+     * @param string|null $text Some text containing white spaces
+     *
+     * @return self
+     */
+    public function setText($text)
+    {
+        if (is_null($text)) {
+            throw new \InvalidArgumentException('non-nullable text cannot be null');
+        }
+        $this->container['text'] = $text;
+
+        return $this;
+    }
+
+    /**
+     * Gets date
+     *
+     * @return \DateTime|null
+     */
+    public function getDate()
+    {
+        return $this->container['date'];
+    }
+
+    /**
+     * Sets date
+     *
+     * @param \DateTime|null $date A date
+     *
+     * @return self
+     */
+    public function setDate($date)
+    {
+        if (is_null($date)) {
+            throw new \InvalidArgumentException('non-nullable date cannot be null');
+        }
+        $this->container['date'] = $date;
+
+        return $this;
+    }
+    /**
+     * Returns true if offset exists. False otherwise.
+     *
+     * @param integer $offset Offset
+     *
+     * @return boolean
+     */
+    public function offsetExists($offset): bool
+    {
+        return isset($this->container[$offset]);
+    }
+
+    /**
+     * Gets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return mixed|null
+     */
+    #[\ReturnTypeWillChange]
+    public function offsetGet($offset)
+    {
+        return $this->container[$offset] ?? null;
+    }
+
+    /**
+     * Sets value based on offset.
+     *
+     * @param int|null $offset Offset
+     * @param mixed    $value  Value to be set
+     *
+     * @return void
+     */
+    public function offsetSet($offset, $value): void
+    {
+        if (is_null($offset)) {
+            $this->container[] = $value;
+        } else {
+            $this->container[$offset] = $value;
+        }
+    }
+
+    /**
+     * Unsets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return void
+     */
+    public function offsetUnset($offset): void
+    {
+        unset($this->container[$offset]);
+    }
+
+    /**
+     * Serializes the object to a value that can be serialized natively by json_encode().
+     * @link https://www.php.net/manual/en/jsonserializable.jsonserialize.php
+     *
+     * @return mixed Returns data which can be serialized by json_encode(), which is a value
+     * of any type other than a resource.
+     */
+    #[\ReturnTypeWillChange]
+    public function jsonSerialize()
+    {
+       return ObjectSerializer::sanitizeForSerialization($this);
+    }
+
+    /**
+     * Gets the string presentation of the object
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return json_encode(
+            ObjectSerializer::sanitizeForSerialization($this),
+            JSON_PRETTY_PRINT
+        );
+    }
+
+    /**
+     * Gets a header-safe presentation of the object
+     *
+     * @return string
+     */
+    public function toHeaderValue()
+    {
+        return json_encode(ObjectSerializer::sanitizeForSerialization($this));
+    }
+}
+
+

samples/client/echo_api/php-nextgen/src/Model/DefaultValue.php

@@ -0,0 +1,696 @@
+<?php
+/**
+ * DefaultValue
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client\Model;
+
+use \ArrayAccess;
+use \OpenAPI\Client\ObjectSerializer;
+
+/**
+ * DefaultValue Class Doc Comment
+ *
+ * @category Class
+ * @description to test the default value of properties
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ * @implements \ArrayAccess<string, mixed>
+ */
+class DefaultValue implements ModelInterface, ArrayAccess, \JsonSerializable
+{
+    public const DISCRIMINATOR = null;
+
+    /**
+      * The original name of the model.
+      *
+      * @var string
+      */
+    protected static $openAPIModelName = 'DefaultValue';
+
+    /**
+      * Array of property to type mappings. Used for (de)serialization
+      *
+      * @var string[]
+      */
+    protected static $openAPITypes = [
+        'array_string_enum_ref_default' => '\OpenAPI\Client\Model\StringEnumRef[]',
+        'array_string_enum_default' => 'string[]',
+        'array_string_default' => 'string[]',
+        'array_integer_default' => 'int[]',
+        'array_string' => 'string[]',
+        'array_string_nullable' => 'string[]',
+        'array_string_extension_nullable' => 'string[]',
+        'string_nullable' => 'string'
+    ];
+
+    /**
+      * Array of property to format mappings. Used for (de)serialization
+      *
+      * @var string[]
+      * @phpstan-var array<string, string|null>
+      * @psalm-var array<string, string|null>
+      */
+    protected static $openAPIFormats = [
+        'array_string_enum_ref_default' => null,
+        'array_string_enum_default' => null,
+        'array_string_default' => null,
+        'array_integer_default' => null,
+        'array_string' => null,
+        'array_string_nullable' => null,
+        'array_string_extension_nullable' => null,
+        'string_nullable' => null
+    ];
+
+    /**
+      * Array of nullable properties. Used for (de)serialization
+      *
+      * @var boolean[]
+      */
+    protected static array $openAPINullables = [
+        'array_string_enum_ref_default' => false,
+		'array_string_enum_default' => false,
+		'array_string_default' => false,
+		'array_integer_default' => false,
+		'array_string' => false,
+		'array_string_nullable' => true,
+		'array_string_extension_nullable' => true,
+		'string_nullable' => true
+    ];
+
+    /**
+      * If a nullable field gets set to null, insert it here
+      *
+      * @var boolean[]
+      */
+    protected array $openAPINullablesSetToNull = [];
+
+    /**
+     * Array of property to type mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPITypes()
+    {
+        return self::$openAPITypes;
+    }
+
+    /**
+     * Array of property to format mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPIFormats()
+    {
+        return self::$openAPIFormats;
+    }
+
+    /**
+     * Array of nullable properties
+     *
+     * @return array
+     */
+    protected static function openAPINullables(): array
+    {
+        return self::$openAPINullables;
+    }
+
+    /**
+     * Array of nullable field names deliberately set to null
+     *
+     * @return boolean[]
+     */
+    private function getOpenAPINullablesSetToNull(): array
+    {
+        return $this->openAPINullablesSetToNull;
+    }
+
+    /**
+     * Setter - Array of nullable field names deliberately set to null
+     *
+     * @param boolean[] $openAPINullablesSetToNull
+     */
+    private function setOpenAPINullablesSetToNull(array $openAPINullablesSetToNull): void
+    {
+        $this->openAPINullablesSetToNull = $openAPINullablesSetToNull;
+    }
+
+    /**
+     * Checks if a property is nullable
+     *
+     * @param string $property
+     * @return bool
+     */
+    public static function isNullable(string $property): bool
+    {
+        return self::openAPINullables()[$property] ?? false;
+    }
+
+    /**
+     * Checks if a nullable property is set to null.
+     *
+     * @param string $property
+     * @return bool
+     */
+    public function isNullableSetToNull(string $property): bool
+    {
+        return in_array($property, $this->getOpenAPINullablesSetToNull(), true);
+    }
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @var string[]
+     */
+    protected static $attributeMap = [
+        'array_string_enum_ref_default' => 'array_string_enum_ref_default',
+        'array_string_enum_default' => 'array_string_enum_default',
+        'array_string_default' => 'array_string_default',
+        'array_integer_default' => 'array_integer_default',
+        'array_string' => 'array_string',
+        'array_string_nullable' => 'array_string_nullable',
+        'array_string_extension_nullable' => 'array_string_extension_nullable',
+        'string_nullable' => 'string_nullable'
+    ];
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @var string[]
+     */
+    protected static $setters = [
+        'array_string_enum_ref_default' => 'setArrayStringEnumRefDefault',
+        'array_string_enum_default' => 'setArrayStringEnumDefault',
+        'array_string_default' => 'setArrayStringDefault',
+        'array_integer_default' => 'setArrayIntegerDefault',
+        'array_string' => 'setArrayString',
+        'array_string_nullable' => 'setArrayStringNullable',
+        'array_string_extension_nullable' => 'setArrayStringExtensionNullable',
+        'string_nullable' => 'setStringNullable'
+    ];
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @var string[]
+     */
+    protected static $getters = [
+        'array_string_enum_ref_default' => 'getArrayStringEnumRefDefault',
+        'array_string_enum_default' => 'getArrayStringEnumDefault',
+        'array_string_default' => 'getArrayStringDefault',
+        'array_integer_default' => 'getArrayIntegerDefault',
+        'array_string' => 'getArrayString',
+        'array_string_nullable' => 'getArrayStringNullable',
+        'array_string_extension_nullable' => 'getArrayStringExtensionNullable',
+        'string_nullable' => 'getStringNullable'
+    ];
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @return array
+     */
+    public static function attributeMap()
+    {
+        return self::$attributeMap;
+    }
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @return array
+     */
+    public static function setters()
+    {
+        return self::$setters;
+    }
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @return array
+     */
+    public static function getters()
+    {
+        return self::$getters;
+    }
+
+    /**
+     * The original name of the model.
+     *
+     * @return string
+     */
+    public function getModelName()
+    {
+        return self::$openAPIModelName;
+    }
+
+    public const ARRAY_STRING_ENUM_DEFAULT_SUCCESS = 'success';
+    public const ARRAY_STRING_ENUM_DEFAULT_FAILURE = 'failure';
+    public const ARRAY_STRING_ENUM_DEFAULT_UNCLASSIFIED = 'unclassified';
+
+    /**
+     * Gets allowable values of the enum
+     *
+     * @return string[]
+     */
+    public function getArrayStringEnumDefaultAllowableValues()
+    {
+        return [
+            self::ARRAY_STRING_ENUM_DEFAULT_SUCCESS,
+            self::ARRAY_STRING_ENUM_DEFAULT_FAILURE,
+            self::ARRAY_STRING_ENUM_DEFAULT_UNCLASSIFIED,
+        ];
+    }
+
+    /**
+     * Associative array for storing property values
+     *
+     * @var mixed[]
+     */
+    protected $container = [];
+
+    /**
+     * Constructor
+     *
+     * @param mixed[] $data Associated array of property values
+     *                      initializing the model
+     */
+    public function __construct(array $data = null)
+    {
+        $this->setIfExists('array_string_enum_ref_default', $data ?? [], null);
+        $this->setIfExists('array_string_enum_default', $data ?? [], null);
+        $this->setIfExists('array_string_default', $data ?? [], null);
+        $this->setIfExists('array_integer_default', $data ?? [], null);
+        $this->setIfExists('array_string', $data ?? [], null);
+        $this->setIfExists('array_string_nullable', $data ?? [], null);
+        $this->setIfExists('array_string_extension_nullable', $data ?? [], null);
+        $this->setIfExists('string_nullable', $data ?? [], null);
+    }
+
+    /**
+    * Sets $this->container[$variableName] to the given data or to the given default Value; if $variableName
+    * is nullable and its value is set to null in the $fields array, then mark it as "set to null" in the
+    * $this->openAPINullablesSetToNull array
+    *
+    * @param string $variableName
+    * @param array  $fields
+    * @param mixed  $defaultValue
+    */
+    private function setIfExists(string $variableName, array $fields, $defaultValue): void
+    {
+        if (self::isNullable($variableName) && array_key_exists($variableName, $fields) && is_null($fields[$variableName])) {
+            $this->openAPINullablesSetToNull[] = $variableName;
+        }
+
+        $this->container[$variableName] = $fields[$variableName] ?? $defaultValue;
+    }
+
+    /**
+     * Show all the invalid properties with reasons.
+     *
+     * @return array invalid properties with reasons
+     */
+    public function listInvalidProperties()
+    {
+        $invalidProperties = [];
+
+        return $invalidProperties;
+    }
+
+    /**
+     * Validate all the properties in the model
+     * return true if all passed
+     *
+     * @return bool True if all properties are valid
+     */
+    public function valid()
+    {
+        return count($this->listInvalidProperties()) === 0;
+    }
+
+
+    /**
+     * Gets array_string_enum_ref_default
+     *
+     * @return \OpenAPI\Client\Model\StringEnumRef[]|null
+     */
+    public function getArrayStringEnumRefDefault()
+    {
+        return $this->container['array_string_enum_ref_default'];
+    }
+
+    /**
+     * Sets array_string_enum_ref_default
+     *
+     * @param \OpenAPI\Client\Model\StringEnumRef[]|null $array_string_enum_ref_default array_string_enum_ref_default
+     *
+     * @return self
+     */
+    public function setArrayStringEnumRefDefault($array_string_enum_ref_default)
+    {
+        if (is_null($array_string_enum_ref_default)) {
+            throw new \InvalidArgumentException('non-nullable array_string_enum_ref_default cannot be null');
+        }
+        $this->container['array_string_enum_ref_default'] = $array_string_enum_ref_default;
+
+        return $this;
+    }
+
+    /**
+     * Gets array_string_enum_default
+     *
+     * @return string[]|null
+     */
+    public function getArrayStringEnumDefault()
+    {
+        return $this->container['array_string_enum_default'];
+    }
+
+    /**
+     * Sets array_string_enum_default
+     *
+     * @param string[]|null $array_string_enum_default array_string_enum_default
+     *
+     * @return self
+     */
+    public function setArrayStringEnumDefault($array_string_enum_default)
+    {
+        if (is_null($array_string_enum_default)) {
+            throw new \InvalidArgumentException('non-nullable array_string_enum_default cannot be null');
+        }
+        $allowedValues = $this->getArrayStringEnumDefaultAllowableValues();
+        if (array_diff($array_string_enum_default, $allowedValues)) {
+            throw new \InvalidArgumentException(
+                sprintf(
+                    "Invalid value for 'array_string_enum_default', must be one of '%s'",
+                    implode("', '", $allowedValues)
+                )
+            );
+        }
+        $this->container['array_string_enum_default'] = $array_string_enum_default;
+
+        return $this;
+    }
+
+    /**
+     * Gets array_string_default
+     *
+     * @return string[]|null
+     */
+    public function getArrayStringDefault()
+    {
+        return $this->container['array_string_default'];
+    }
+
+    /**
+     * Sets array_string_default
+     *
+     * @param string[]|null $array_string_default array_string_default
+     *
+     * @return self
+     */
+    public function setArrayStringDefault($array_string_default)
+    {
+        if (is_null($array_string_default)) {
+            throw new \InvalidArgumentException('non-nullable array_string_default cannot be null');
+        }
+        $this->container['array_string_default'] = $array_string_default;
+
+        return $this;
+    }
+
+    /**
+     * Gets array_integer_default
+     *
+     * @return int[]|null
+     */
+    public function getArrayIntegerDefault()
+    {
+        return $this->container['array_integer_default'];
+    }
+
+    /**
+     * Sets array_integer_default
+     *
+     * @param int[]|null $array_integer_default array_integer_default
+     *
+     * @return self
+     */
+    public function setArrayIntegerDefault($array_integer_default)
+    {
+        if (is_null($array_integer_default)) {
+            throw new \InvalidArgumentException('non-nullable array_integer_default cannot be null');
+        }
+        $this->container['array_integer_default'] = $array_integer_default;
+
+        return $this;
+    }
+
+    /**
+     * Gets array_string
+     *
+     * @return string[]|null
+     */
+    public function getArrayString()
+    {
+        return $this->container['array_string'];
+    }
+
+    /**
+     * Sets array_string
+     *
+     * @param string[]|null $array_string array_string
+     *
+     * @return self
+     */
+    public function setArrayString($array_string)
+    {
+        if (is_null($array_string)) {
+            throw new \InvalidArgumentException('non-nullable array_string cannot be null');
+        }
+        $this->container['array_string'] = $array_string;
+
+        return $this;
+    }
+
+    /**
+     * Gets array_string_nullable
+     *
+     * @return string[]|null
+     */
+    public function getArrayStringNullable()
+    {
+        return $this->container['array_string_nullable'];
+    }
+
+    /**
+     * Sets array_string_nullable
+     *
+     * @param string[]|null $array_string_nullable array_string_nullable
+     *
+     * @return self
+     */
+    public function setArrayStringNullable($array_string_nullable)
+    {
+        if (is_null($array_string_nullable)) {
+            array_push($this->openAPINullablesSetToNull, 'array_string_nullable');
+        } else {
+            $nullablesSetToNull = $this->getOpenAPINullablesSetToNull();
+            $index = array_search('array_string_nullable', $nullablesSetToNull);
+            if ($index !== FALSE) {
+                unset($nullablesSetToNull[$index]);
+                $this->setOpenAPINullablesSetToNull($nullablesSetToNull);
+            }
+        }
+        $this->container['array_string_nullable'] = $array_string_nullable;
+
+        return $this;
+    }
+
+    /**
+     * Gets array_string_extension_nullable
+     *
+     * @return string[]|null
+     */
+    public function getArrayStringExtensionNullable()
+    {
+        return $this->container['array_string_extension_nullable'];
+    }
+
+    /**
+     * Sets array_string_extension_nullable
+     *
+     * @param string[]|null $array_string_extension_nullable array_string_extension_nullable
+     *
+     * @return self
+     */
+    public function setArrayStringExtensionNullable($array_string_extension_nullable)
+    {
+        if (is_null($array_string_extension_nullable)) {
+            array_push($this->openAPINullablesSetToNull, 'array_string_extension_nullable');
+        } else {
+            $nullablesSetToNull = $this->getOpenAPINullablesSetToNull();
+            $index = array_search('array_string_extension_nullable', $nullablesSetToNull);
+            if ($index !== FALSE) {
+                unset($nullablesSetToNull[$index]);
+                $this->setOpenAPINullablesSetToNull($nullablesSetToNull);
+            }
+        }
+        $this->container['array_string_extension_nullable'] = $array_string_extension_nullable;
+
+        return $this;
+    }
+
+    /**
+     * Gets string_nullable
+     *
+     * @return string|null
+     */
+    public function getStringNullable()
+    {
+        return $this->container['string_nullable'];
+    }
+
+    /**
+     * Sets string_nullable
+     *
+     * @param string|null $string_nullable string_nullable
+     *
+     * @return self
+     */
+    public function setStringNullable($string_nullable)
+    {
+        if (is_null($string_nullable)) {
+            array_push($this->openAPINullablesSetToNull, 'string_nullable');
+        } else {
+            $nullablesSetToNull = $this->getOpenAPINullablesSetToNull();
+            $index = array_search('string_nullable', $nullablesSetToNull);
+            if ($index !== FALSE) {
+                unset($nullablesSetToNull[$index]);
+                $this->setOpenAPINullablesSetToNull($nullablesSetToNull);
+            }
+        }
+        $this->container['string_nullable'] = $string_nullable;
+
+        return $this;
+    }
+    /**
+     * Returns true if offset exists. False otherwise.
+     *
+     * @param integer $offset Offset
+     *
+     * @return boolean
+     */
+    public function offsetExists($offset): bool
+    {
+        return isset($this->container[$offset]);
+    }
+
+    /**
+     * Gets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return mixed|null
+     */
+    #[\ReturnTypeWillChange]
+    public function offsetGet($offset)
+    {
+        return $this->container[$offset] ?? null;
+    }
+
+    /**
+     * Sets value based on offset.
+     *
+     * @param int|null $offset Offset
+     * @param mixed    $value  Value to be set
+     *
+     * @return void
+     */
+    public function offsetSet($offset, $value): void
+    {
+        if (is_null($offset)) {
+            $this->container[] = $value;
+        } else {
+            $this->container[$offset] = $value;
+        }
+    }
+
+    /**
+     * Unsets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return void
+     */
+    public function offsetUnset($offset): void
+    {
+        unset($this->container[$offset]);
+    }
+
+    /**
+     * Serializes the object to a value that can be serialized natively by json_encode().
+     * @link https://www.php.net/manual/en/jsonserializable.jsonserialize.php
+     *
+     * @return mixed Returns data which can be serialized by json_encode(), which is a value
+     * of any type other than a resource.
+     */
+    #[\ReturnTypeWillChange]
+    public function jsonSerialize()
+    {
+       return ObjectSerializer::sanitizeForSerialization($this);
+    }
+
+    /**
+     * Gets the string presentation of the object
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return json_encode(
+            ObjectSerializer::sanitizeForSerialization($this),
+            JSON_PRETTY_PRINT
+        );
+    }
+
+    /**
+     * Gets a header-safe presentation of the object
+     *
+     * @return string
+     */
+    public function toHeaderValue()
+    {
+        return json_encode(ObjectSerializer::sanitizeForSerialization($this));
+    }
+}
+
+

samples/client/echo_api/php-nextgen/src/Model/ModelInterface.php

@@ -0,0 +1,112 @@
+<?php
+/**
+ * ModelInterface
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client\Model
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client\Model;
+
+/**
+ * Interface abstracting model access.
+ *
+ * @package OpenAPI\Client\Model
+ * @author  OpenAPI Generator team
+ */
+interface ModelInterface
+{
+    /**
+     * The original name of the model.
+     *
+     * @return string
+     */
+    public function getModelName();
+
+    /**
+     * Array of property to type mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPITypes();
+
+    /**
+     * Array of property to format mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPIFormats();
+
+    /**
+     * Array of attributes where the key is the local name, and the value is the original name
+     *
+     * @return array
+     */
+    public static function attributeMap();
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @return array
+     */
+    public static function setters();
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @return array
+     */
+    public static function getters();
+
+    /**
+     * Show all the invalid properties with reasons.
+     *
+     * @return array
+     */
+    public function listInvalidProperties();
+
+    /**
+     * Validate all the properties in the model
+     * return true if all passed
+     *
+     * @return bool
+     */
+    public function valid();
+
+    /**
+     * Checks if a property is nullable
+     *
+     * @param string $property
+     * @return bool
+     */
+    public static function isNullable(string $property): bool;
+
+    /**
+     * Checks if a nullable property is set to null.
+     *
+     * @param string $property
+     * @return bool
+     */
+    public function isNullableSetToNull(string $property): bool;
+}

samples/client/echo_api/php-nextgen/src/Model/NumberPropertiesOnly.php

@@ -0,0 +1,494 @@
+<?php
+/**
+ * NumberPropertiesOnly
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client\Model;
+
+use \ArrayAccess;
+use \OpenAPI\Client\ObjectSerializer;
+
+/**
+ * NumberPropertiesOnly Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ * @implements \ArrayAccess<string, mixed>
+ */
+class NumberPropertiesOnly implements ModelInterface, ArrayAccess, \JsonSerializable
+{
+    public const DISCRIMINATOR = null;
+
+    /**
+      * The original name of the model.
+      *
+      * @var string
+      */
+    protected static $openAPIModelName = 'NumberPropertiesOnly';
+
+    /**
+      * Array of property to type mappings. Used for (de)serialization
+      *
+      * @var string[]
+      */
+    protected static $openAPITypes = [
+        'number' => 'float',
+        'float' => 'float',
+        'double' => 'float'
+    ];
+
+    /**
+      * Array of property to format mappings. Used for (de)serialization
+      *
+      * @var string[]
+      * @phpstan-var array<string, string|null>
+      * @psalm-var array<string, string|null>
+      */
+    protected static $openAPIFormats = [
+        'number' => null,
+        'float' => 'float',
+        'double' => 'double'
+    ];
+
+    /**
+      * Array of nullable properties. Used for (de)serialization
+      *
+      * @var boolean[]
+      */
+    protected static array $openAPINullables = [
+        'number' => false,
+		'float' => false,
+		'double' => false
+    ];
+
+    /**
+      * If a nullable field gets set to null, insert it here
+      *
+      * @var boolean[]
+      */
+    protected array $openAPINullablesSetToNull = [];
+
+    /**
+     * Array of property to type mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPITypes()
+    {
+        return self::$openAPITypes;
+    }
+
+    /**
+     * Array of property to format mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPIFormats()
+    {
+        return self::$openAPIFormats;
+    }
+
+    /**
+     * Array of nullable properties
+     *
+     * @return array
+     */
+    protected static function openAPINullables(): array
+    {
+        return self::$openAPINullables;
+    }
+
+    /**
+     * Array of nullable field names deliberately set to null
+     *
+     * @return boolean[]
+     */
+    private function getOpenAPINullablesSetToNull(): array
+    {
+        return $this->openAPINullablesSetToNull;
+    }
+
+    /**
+     * Setter - Array of nullable field names deliberately set to null
+     *
+     * @param boolean[] $openAPINullablesSetToNull
+     */
+    private function setOpenAPINullablesSetToNull(array $openAPINullablesSetToNull): void
+    {
+        $this->openAPINullablesSetToNull = $openAPINullablesSetToNull;
+    }
+
+    /**
+     * Checks if a property is nullable
+     *
+     * @param string $property
+     * @return bool
+     */
+    public static function isNullable(string $property): bool
+    {
+        return self::openAPINullables()[$property] ?? false;
+    }
+
+    /**
+     * Checks if a nullable property is set to null.
+     *
+     * @param string $property
+     * @return bool
+     */
+    public function isNullableSetToNull(string $property): bool
+    {
+        return in_array($property, $this->getOpenAPINullablesSetToNull(), true);
+    }
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @var string[]
+     */
+    protected static $attributeMap = [
+        'number' => 'number',
+        'float' => 'float',
+        'double' => 'double'
+    ];
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @var string[]
+     */
+    protected static $setters = [
+        'number' => 'setNumber',
+        'float' => 'setFloat',
+        'double' => 'setDouble'
+    ];
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @var string[]
+     */
+    protected static $getters = [
+        'number' => 'getNumber',
+        'float' => 'getFloat',
+        'double' => 'getDouble'
+    ];
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @return array
+     */
+    public static function attributeMap()
+    {
+        return self::$attributeMap;
+    }
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @return array
+     */
+    public static function setters()
+    {
+        return self::$setters;
+    }
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @return array
+     */
+    public static function getters()
+    {
+        return self::$getters;
+    }
+
+    /**
+     * The original name of the model.
+     *
+     * @return string
+     */
+    public function getModelName()
+    {
+        return self::$openAPIModelName;
+    }
+
+
+    /**
+     * Associative array for storing property values
+     *
+     * @var mixed[]
+     */
+    protected $container = [];
+
+    /**
+     * Constructor
+     *
+     * @param mixed[] $data Associated array of property values
+     *                      initializing the model
+     */
+    public function __construct(array $data = null)
+    {
+        $this->setIfExists('number', $data ?? [], null);
+        $this->setIfExists('float', $data ?? [], null);
+        $this->setIfExists('double', $data ?? [], null);
+    }
+
+    /**
+    * Sets $this->container[$variableName] to the given data or to the given default Value; if $variableName
+    * is nullable and its value is set to null in the $fields array, then mark it as "set to null" in the
+    * $this->openAPINullablesSetToNull array
+    *
+    * @param string $variableName
+    * @param array  $fields
+    * @param mixed  $defaultValue
+    */
+    private function setIfExists(string $variableName, array $fields, $defaultValue): void
+    {
+        if (self::isNullable($variableName) && array_key_exists($variableName, $fields) && is_null($fields[$variableName])) {
+            $this->openAPINullablesSetToNull[] = $variableName;
+        }
+
+        $this->container[$variableName] = $fields[$variableName] ?? $defaultValue;
+    }
+
+    /**
+     * Show all the invalid properties with reasons.
+     *
+     * @return array invalid properties with reasons
+     */
+    public function listInvalidProperties()
+    {
+        $invalidProperties = [];
+
+        if (!is_null($this->container['double']) && ($this->container['double'] > 50.2)) {
+            $invalidProperties[] = "invalid value for 'double', must be smaller than or equal to 50.2.";
+        }
+
+        if (!is_null($this->container['double']) && ($this->container['double'] < 0.8)) {
+            $invalidProperties[] = "invalid value for 'double', must be bigger than or equal to 0.8.";
+        }
+
+        return $invalidProperties;
+    }
+
+    /**
+     * Validate all the properties in the model
+     * return true if all passed
+     *
+     * @return bool True if all properties are valid
+     */
+    public function valid()
+    {
+        return count($this->listInvalidProperties()) === 0;
+    }
+
+
+    /**
+     * Gets number
+     *
+     * @return float|null
+     */
+    public function getNumber()
+    {
+        return $this->container['number'];
+    }
+
+    /**
+     * Sets number
+     *
+     * @param float|null $number number
+     *
+     * @return self
+     */
+    public function setNumber($number)
+    {
+        if (is_null($number)) {
+            throw new \InvalidArgumentException('non-nullable number cannot be null');
+        }
+        $this->container['number'] = $number;
+
+        return $this;
+    }
+
+    /**
+     * Gets float
+     *
+     * @return float|null
+     */
+    public function getFloat()
+    {
+        return $this->container['float'];
+    }
+
+    /**
+     * Sets float
+     *
+     * @param float|null $float float
+     *
+     * @return self
+     */
+    public function setFloat($float)
+    {
+        if (is_null($float)) {
+            throw new \InvalidArgumentException('non-nullable float cannot be null');
+        }
+        $this->container['float'] = $float;
+
+        return $this;
+    }
+
+    /**
+     * Gets double
+     *
+     * @return float|null
+     */
+    public function getDouble()
+    {
+        return $this->container['double'];
+    }
+
+    /**
+     * Sets double
+     *
+     * @param float|null $double double
+     *
+     * @return self
+     */
+    public function setDouble($double)
+    {
+        if (is_null($double)) {
+            throw new \InvalidArgumentException('non-nullable double cannot be null');
+        }
+
+        if (($double > 50.2)) {
+            throw new \InvalidArgumentException('invalid value for $double when calling NumberPropertiesOnly., must be smaller than or equal to 50.2.');
+        }
+        if (($double < 0.8)) {
+            throw new \InvalidArgumentException('invalid value for $double when calling NumberPropertiesOnly., must be bigger than or equal to 0.8.');
+        }
+
+        $this->container['double'] = $double;
+
+        return $this;
+    }
+    /**
+     * Returns true if offset exists. False otherwise.
+     *
+     * @param integer $offset Offset
+     *
+     * @return boolean
+     */
+    public function offsetExists($offset): bool
+    {
+        return isset($this->container[$offset]);
+    }
+
+    /**
+     * Gets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return mixed|null
+     */
+    #[\ReturnTypeWillChange]
+    public function offsetGet($offset)
+    {
+        return $this->container[$offset] ?? null;
+    }
+
+    /**
+     * Sets value based on offset.
+     *
+     * @param int|null $offset Offset
+     * @param mixed    $value  Value to be set
+     *
+     * @return void
+     */
+    public function offsetSet($offset, $value): void
+    {
+        if (is_null($offset)) {
+            $this->container[] = $value;
+        } else {
+            $this->container[$offset] = $value;
+        }
+    }
+
+    /**
+     * Unsets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return void
+     */
+    public function offsetUnset($offset): void
+    {
+        unset($this->container[$offset]);
+    }
+
+    /**
+     * Serializes the object to a value that can be serialized natively by json_encode().
+     * @link https://www.php.net/manual/en/jsonserializable.jsonserialize.php
+     *
+     * @return mixed Returns data which can be serialized by json_encode(), which is a value
+     * of any type other than a resource.
+     */
+    #[\ReturnTypeWillChange]
+    public function jsonSerialize()
+    {
+       return ObjectSerializer::sanitizeForSerialization($this);
+    }
+
+    /**
+     * Gets the string presentation of the object
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return json_encode(
+            ObjectSerializer::sanitizeForSerialization($this),
+            JSON_PRETTY_PRINT
+        );
+    }
+
+    /**
+     * Gets a header-safe presentation of the object
+     *
+     * @return string
+     */
+    public function toHeaderValue()
+    {
+        return json_encode(ObjectSerializer::sanitizeForSerialization($this));
+    }
+}
+
+

samples/client/echo_api/php-nextgen/src/Model/Pet.php

@@ -0,0 +1,622 @@
+<?php
+/**
+ * Pet
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client\Model;
+
+use \ArrayAccess;
+use \OpenAPI\Client\ObjectSerializer;
+
+/**
+ * Pet Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ * @implements \ArrayAccess<string, mixed>
+ */
+class Pet implements ModelInterface, ArrayAccess, \JsonSerializable
+{
+    public const DISCRIMINATOR = null;
+
+    /**
+      * The original name of the model.
+      *
+      * @var string
+      */
+    protected static $openAPIModelName = 'Pet';
+
+    /**
+      * Array of property to type mappings. Used for (de)serialization
+      *
+      * @var string[]
+      */
+    protected static $openAPITypes = [
+        'id' => 'int',
+        'name' => 'string',
+        'category' => '\OpenAPI\Client\Model\Category',
+        'photo_urls' => 'string[]',
+        'tags' => '\OpenAPI\Client\Model\Tag[]',
+        'status' => 'string'
+    ];
+
+    /**
+      * Array of property to format mappings. Used for (de)serialization
+      *
+      * @var string[]
+      * @phpstan-var array<string, string|null>
+      * @psalm-var array<string, string|null>
+      */
+    protected static $openAPIFormats = [
+        'id' => 'int64',
+        'name' => null,
+        'category' => null,
+        'photo_urls' => null,
+        'tags' => null,
+        'status' => null
+    ];
+
+    /**
+      * Array of nullable properties. Used for (de)serialization
+      *
+      * @var boolean[]
+      */
+    protected static array $openAPINullables = [
+        'id' => false,
+		'name' => false,
+		'category' => false,
+		'photo_urls' => false,
+		'tags' => false,
+		'status' => false
+    ];
+
+    /**
+      * If a nullable field gets set to null, insert it here
+      *
+      * @var boolean[]
+      */
+    protected array $openAPINullablesSetToNull = [];
+
+    /**
+     * Array of property to type mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPITypes()
+    {
+        return self::$openAPITypes;
+    }
+
+    /**
+     * Array of property to format mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPIFormats()
+    {
+        return self::$openAPIFormats;
+    }
+
+    /**
+     * Array of nullable properties
+     *
+     * @return array
+     */
+    protected static function openAPINullables(): array
+    {
+        return self::$openAPINullables;
+    }
+
+    /**
+     * Array of nullable field names deliberately set to null
+     *
+     * @return boolean[]
+     */
+    private function getOpenAPINullablesSetToNull(): array
+    {
+        return $this->openAPINullablesSetToNull;
+    }
+
+    /**
+     * Setter - Array of nullable field names deliberately set to null
+     *
+     * @param boolean[] $openAPINullablesSetToNull
+     */
+    private function setOpenAPINullablesSetToNull(array $openAPINullablesSetToNull): void
+    {
+        $this->openAPINullablesSetToNull = $openAPINullablesSetToNull;
+    }
+
+    /**
+     * Checks if a property is nullable
+     *
+     * @param string $property
+     * @return bool
+     */
+    public static function isNullable(string $property): bool
+    {
+        return self::openAPINullables()[$property] ?? false;
+    }
+
+    /**
+     * Checks if a nullable property is set to null.
+     *
+     * @param string $property
+     * @return bool
+     */
+    public function isNullableSetToNull(string $property): bool
+    {
+        return in_array($property, $this->getOpenAPINullablesSetToNull(), true);
+    }
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @var string[]
+     */
+    protected static $attributeMap = [
+        'id' => 'id',
+        'name' => 'name',
+        'category' => 'category',
+        'photo_urls' => 'photoUrls',
+        'tags' => 'tags',
+        'status' => 'status'
+    ];
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @var string[]
+     */
+    protected static $setters = [
+        'id' => 'setId',
+        'name' => 'setName',
+        'category' => 'setCategory',
+        'photo_urls' => 'setPhotoUrls',
+        'tags' => 'setTags',
+        'status' => 'setStatus'
+    ];
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @var string[]
+     */
+    protected static $getters = [
+        'id' => 'getId',
+        'name' => 'getName',
+        'category' => 'getCategory',
+        'photo_urls' => 'getPhotoUrls',
+        'tags' => 'getTags',
+        'status' => 'getStatus'
+    ];
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @return array
+     */
+    public static function attributeMap()
+    {
+        return self::$attributeMap;
+    }
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @return array
+     */
+    public static function setters()
+    {
+        return self::$setters;
+    }
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @return array
+     */
+    public static function getters()
+    {
+        return self::$getters;
+    }
+
+    /**
+     * The original name of the model.
+     *
+     * @return string
+     */
+    public function getModelName()
+    {
+        return self::$openAPIModelName;
+    }
+
+    public const STATUS_AVAILABLE = 'available';
+    public const STATUS_PENDING = 'pending';
+    public const STATUS_SOLD = 'sold';
+
+    /**
+     * Gets allowable values of the enum
+     *
+     * @return string[]
+     */
+    public function getStatusAllowableValues()
+    {
+        return [
+            self::STATUS_AVAILABLE,
+            self::STATUS_PENDING,
+            self::STATUS_SOLD,
+        ];
+    }
+
+    /**
+     * Associative array for storing property values
+     *
+     * @var mixed[]
+     */
+    protected $container = [];
+
+    /**
+     * Constructor
+     *
+     * @param mixed[] $data Associated array of property values
+     *                      initializing the model
+     */
+    public function __construct(array $data = null)
+    {
+        $this->setIfExists('id', $data ?? [], null);
+        $this->setIfExists('name', $data ?? [], null);
+        $this->setIfExists('category', $data ?? [], null);
+        $this->setIfExists('photo_urls', $data ?? [], null);
+        $this->setIfExists('tags', $data ?? [], null);
+        $this->setIfExists('status', $data ?? [], null);
+    }
+
+    /**
+    * Sets $this->container[$variableName] to the given data or to the given default Value; if $variableName
+    * is nullable and its value is set to null in the $fields array, then mark it as "set to null" in the
+    * $this->openAPINullablesSetToNull array
+    *
+    * @param string $variableName
+    * @param array  $fields
+    * @param mixed  $defaultValue
+    */
+    private function setIfExists(string $variableName, array $fields, $defaultValue): void
+    {
+        if (self::isNullable($variableName) && array_key_exists($variableName, $fields) && is_null($fields[$variableName])) {
+            $this->openAPINullablesSetToNull[] = $variableName;
+        }
+
+        $this->container[$variableName] = $fields[$variableName] ?? $defaultValue;
+    }
+
+    /**
+     * Show all the invalid properties with reasons.
+     *
+     * @return array invalid properties with reasons
+     */
+    public function listInvalidProperties()
+    {
+        $invalidProperties = [];
+
+        if ($this->container['name'] === null) {
+            $invalidProperties[] = "'name' can't be null";
+        }
+        if ($this->container['photo_urls'] === null) {
+            $invalidProperties[] = "'photo_urls' can't be null";
+        }
+        $allowedValues = $this->getStatusAllowableValues();
+        if (!is_null($this->container['status']) && !in_array($this->container['status'], $allowedValues, true)) {
+            $invalidProperties[] = sprintf(
+                "invalid value '%s' for 'status', must be one of '%s'",
+                $this->container['status'],
+                implode("', '", $allowedValues)
+            );
+        }
+
+        return $invalidProperties;
+    }
+
+    /**
+     * Validate all the properties in the model
+     * return true if all passed
+     *
+     * @return bool True if all properties are valid
+     */
+    public function valid()
+    {
+        return count($this->listInvalidProperties()) === 0;
+    }
+
+
+    /**
+     * Gets id
+     *
+     * @return int|null
+     */
+    public function getId()
+    {
+        return $this->container['id'];
+    }
+
+    /**
+     * Sets id
+     *
+     * @param int|null $id id
+     *
+     * @return self
+     */
+    public function setId($id)
+    {
+        if (is_null($id)) {
+            throw new \InvalidArgumentException('non-nullable id cannot be null');
+        }
+        $this->container['id'] = $id;
+
+        return $this;
+    }
+
+    /**
+     * Gets name
+     *
+     * @return string
+     */
+    public function getName()
+    {
+        return $this->container['name'];
+    }
+
+    /**
+     * Sets name
+     *
+     * @param string $name name
+     *
+     * @return self
+     */
+    public function setName($name)
+    {
+        if (is_null($name)) {
+            throw new \InvalidArgumentException('non-nullable name cannot be null');
+        }
+        $this->container['name'] = $name;
+
+        return $this;
+    }
+
+    /**
+     * Gets category
+     *
+     * @return \OpenAPI\Client\Model\Category|null
+     */
+    public function getCategory()
+    {
+        return $this->container['category'];
+    }
+
+    /**
+     * Sets category
+     *
+     * @param \OpenAPI\Client\Model\Category|null $category category
+     *
+     * @return self
+     */
+    public function setCategory($category)
+    {
+        if (is_null($category)) {
+            throw new \InvalidArgumentException('non-nullable category cannot be null');
+        }
+        $this->container['category'] = $category;
+
+        return $this;
+    }
+
+    /**
+     * Gets photo_urls
+     *
+     * @return string[]
+     */
+    public function getPhotoUrls()
+    {
+        return $this->container['photo_urls'];
+    }
+
+    /**
+     * Sets photo_urls
+     *
+     * @param string[] $photo_urls photo_urls
+     *
+     * @return self
+     */
+    public function setPhotoUrls($photo_urls)
+    {
+        if (is_null($photo_urls)) {
+            throw new \InvalidArgumentException('non-nullable photo_urls cannot be null');
+        }
+        $this->container['photo_urls'] = $photo_urls;
+
+        return $this;
+    }
+
+    /**
+     * Gets tags
+     *
+     * @return \OpenAPI\Client\Model\Tag[]|null
+     */
+    public function getTags()
+    {
+        return $this->container['tags'];
+    }
+
+    /**
+     * Sets tags
+     *
+     * @param \OpenAPI\Client\Model\Tag[]|null $tags tags
+     *
+     * @return self
+     */
+    public function setTags($tags)
+    {
+        if (is_null($tags)) {
+            throw new \InvalidArgumentException('non-nullable tags cannot be null');
+        }
+        $this->container['tags'] = $tags;
+
+        return $this;
+    }
+
+    /**
+     * Gets status
+     *
+     * @return string|null
+     */
+    public function getStatus()
+    {
+        return $this->container['status'];
+    }
+
+    /**
+     * Sets status
+     *
+     * @param string|null $status pet status in the store
+     *
+     * @return self
+     */
+    public function setStatus($status)
+    {
+        if (is_null($status)) {
+            throw new \InvalidArgumentException('non-nullable status cannot be null');
+        }
+        $allowedValues = $this->getStatusAllowableValues();
+        if (!in_array($status, $allowedValues, true)) {
+            throw new \InvalidArgumentException(
+                sprintf(
+                    "Invalid value '%s' for 'status', must be one of '%s'",
+                    $status,
+                    implode("', '", $allowedValues)
+                )
+            );
+        }
+        $this->container['status'] = $status;
+
+        return $this;
+    }
+    /**
+     * Returns true if offset exists. False otherwise.
+     *
+     * @param integer $offset Offset
+     *
+     * @return boolean
+     */
+    public function offsetExists($offset): bool
+    {
+        return isset($this->container[$offset]);
+    }
+
+    /**
+     * Gets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return mixed|null
+     */
+    #[\ReturnTypeWillChange]
+    public function offsetGet($offset)
+    {
+        return $this->container[$offset] ?? null;
+    }
+
+    /**
+     * Sets value based on offset.
+     *
+     * @param int|null $offset Offset
+     * @param mixed    $value  Value to be set
+     *
+     * @return void
+     */
+    public function offsetSet($offset, $value): void
+    {
+        if (is_null($offset)) {
+            $this->container[] = $value;
+        } else {
+            $this->container[$offset] = $value;
+        }
+    }
+
+    /**
+     * Unsets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return void
+     */
+    public function offsetUnset($offset): void
+    {
+        unset($this->container[$offset]);
+    }
+
+    /**
+     * Serializes the object to a value that can be serialized natively by json_encode().
+     * @link https://www.php.net/manual/en/jsonserializable.jsonserialize.php
+     *
+     * @return mixed Returns data which can be serialized by json_encode(), which is a value
+     * of any type other than a resource.
+     */
+    #[\ReturnTypeWillChange]
+    public function jsonSerialize()
+    {
+       return ObjectSerializer::sanitizeForSerialization($this);
+    }
+
+    /**
+     * Gets the string presentation of the object
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return json_encode(
+            ObjectSerializer::sanitizeForSerialization($this),
+            JSON_PRETTY_PRINT
+        );
+    }
+
+    /**
+     * Gets a header-safe presentation of the object
+     *
+     * @return string
+     */
+    public function toHeaderValue()
+    {
+        return json_encode(ObjectSerializer::sanitizeForSerialization($this));
+    }
+}
+
+

samples/client/echo_api/php-nextgen/src/Model/Query.php

@@ -0,0 +1,470 @@
+<?php
+/**
+ * Query
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client\Model;
+
+use \ArrayAccess;
+use \OpenAPI\Client\ObjectSerializer;
+
+/**
+ * Query Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ * @implements \ArrayAccess<string, mixed>
+ */
+class Query implements ModelInterface, ArrayAccess, \JsonSerializable
+{
+    public const DISCRIMINATOR = null;
+
+    /**
+      * The original name of the model.
+      *
+      * @var string
+      */
+    protected static $openAPIModelName = 'Query';
+
+    /**
+      * Array of property to type mappings. Used for (de)serialization
+      *
+      * @var string[]
+      */
+    protected static $openAPITypes = [
+        'id' => 'int',
+        'outcomes' => 'string[]'
+    ];
+
+    /**
+      * Array of property to format mappings. Used for (de)serialization
+      *
+      * @var string[]
+      * @phpstan-var array<string, string|null>
+      * @psalm-var array<string, string|null>
+      */
+    protected static $openAPIFormats = [
+        'id' => 'int64',
+        'outcomes' => null
+    ];
+
+    /**
+      * Array of nullable properties. Used for (de)serialization
+      *
+      * @var boolean[]
+      */
+    protected static array $openAPINullables = [
+        'id' => false,
+		'outcomes' => false
+    ];
+
+    /**
+      * If a nullable field gets set to null, insert it here
+      *
+      * @var boolean[]
+      */
+    protected array $openAPINullablesSetToNull = [];
+
+    /**
+     * Array of property to type mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPITypes()
+    {
+        return self::$openAPITypes;
+    }
+
+    /**
+     * Array of property to format mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPIFormats()
+    {
+        return self::$openAPIFormats;
+    }
+
+    /**
+     * Array of nullable properties
+     *
+     * @return array
+     */
+    protected static function openAPINullables(): array
+    {
+        return self::$openAPINullables;
+    }
+
+    /**
+     * Array of nullable field names deliberately set to null
+     *
+     * @return boolean[]
+     */
+    private function getOpenAPINullablesSetToNull(): array
+    {
+        return $this->openAPINullablesSetToNull;
+    }
+
+    /**
+     * Setter - Array of nullable field names deliberately set to null
+     *
+     * @param boolean[] $openAPINullablesSetToNull
+     */
+    private function setOpenAPINullablesSetToNull(array $openAPINullablesSetToNull): void
+    {
+        $this->openAPINullablesSetToNull = $openAPINullablesSetToNull;
+    }
+
+    /**
+     * Checks if a property is nullable
+     *
+     * @param string $property
+     * @return bool
+     */
+    public static function isNullable(string $property): bool
+    {
+        return self::openAPINullables()[$property] ?? false;
+    }
+
+    /**
+     * Checks if a nullable property is set to null.
+     *
+     * @param string $property
+     * @return bool
+     */
+    public function isNullableSetToNull(string $property): bool
+    {
+        return in_array($property, $this->getOpenAPINullablesSetToNull(), true);
+    }
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @var string[]
+     */
+    protected static $attributeMap = [
+        'id' => 'id',
+        'outcomes' => 'outcomes'
+    ];
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @var string[]
+     */
+    protected static $setters = [
+        'id' => 'setId',
+        'outcomes' => 'setOutcomes'
+    ];
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @var string[]
+     */
+    protected static $getters = [
+        'id' => 'getId',
+        'outcomes' => 'getOutcomes'
+    ];
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @return array
+     */
+    public static function attributeMap()
+    {
+        return self::$attributeMap;
+    }
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @return array
+     */
+    public static function setters()
+    {
+        return self::$setters;
+    }
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @return array
+     */
+    public static function getters()
+    {
+        return self::$getters;
+    }
+
+    /**
+     * The original name of the model.
+     *
+     * @return string
+     */
+    public function getModelName()
+    {
+        return self::$openAPIModelName;
+    }
+
+    public const OUTCOMES_SUCCESS = 'SUCCESS';
+    public const OUTCOMES_FAILURE = 'FAILURE';
+    public const OUTCOMES_SKIPPED = 'SKIPPED';
+
+    /**
+     * Gets allowable values of the enum
+     *
+     * @return string[]
+     */
+    public function getOutcomesAllowableValues()
+    {
+        return [
+            self::OUTCOMES_SUCCESS,
+            self::OUTCOMES_FAILURE,
+            self::OUTCOMES_SKIPPED,
+        ];
+    }
+
+    /**
+     * Associative array for storing property values
+     *
+     * @var mixed[]
+     */
+    protected $container = [];
+
+    /**
+     * Constructor
+     *
+     * @param mixed[] $data Associated array of property values
+     *                      initializing the model
+     */
+    public function __construct(array $data = null)
+    {
+        $this->setIfExists('id', $data ?? [], null);
+        $this->setIfExists('outcomes', $data ?? [], null);
+    }
+
+    /**
+    * Sets $this->container[$variableName] to the given data or to the given default Value; if $variableName
+    * is nullable and its value is set to null in the $fields array, then mark it as "set to null" in the
+    * $this->openAPINullablesSetToNull array
+    *
+    * @param string $variableName
+    * @param array  $fields
+    * @param mixed  $defaultValue
+    */
+    private function setIfExists(string $variableName, array $fields, $defaultValue): void
+    {
+        if (self::isNullable($variableName) && array_key_exists($variableName, $fields) && is_null($fields[$variableName])) {
+            $this->openAPINullablesSetToNull[] = $variableName;
+        }
+
+        $this->container[$variableName] = $fields[$variableName] ?? $defaultValue;
+    }
+
+    /**
+     * Show all the invalid properties with reasons.
+     *
+     * @return array invalid properties with reasons
+     */
+    public function listInvalidProperties()
+    {
+        $invalidProperties = [];
+
+        return $invalidProperties;
+    }
+
+    /**
+     * Validate all the properties in the model
+     * return true if all passed
+     *
+     * @return bool True if all properties are valid
+     */
+    public function valid()
+    {
+        return count($this->listInvalidProperties()) === 0;
+    }
+
+
+    /**
+     * Gets id
+     *
+     * @return int|null
+     */
+    public function getId()
+    {
+        return $this->container['id'];
+    }
+
+    /**
+     * Sets id
+     *
+     * @param int|null $id Query
+     *
+     * @return self
+     */
+    public function setId($id)
+    {
+        if (is_null($id)) {
+            throw new \InvalidArgumentException('non-nullable id cannot be null');
+        }
+        $this->container['id'] = $id;
+
+        return $this;
+    }
+
+    /**
+     * Gets outcomes
+     *
+     * @return string[]|null
+     */
+    public function getOutcomes()
+    {
+        return $this->container['outcomes'];
+    }
+
+    /**
+     * Sets outcomes
+     *
+     * @param string[]|null $outcomes outcomes
+     *
+     * @return self
+     */
+    public function setOutcomes($outcomes)
+    {
+        if (is_null($outcomes)) {
+            throw new \InvalidArgumentException('non-nullable outcomes cannot be null');
+        }
+        $allowedValues = $this->getOutcomesAllowableValues();
+        if (array_diff($outcomes, $allowedValues)) {
+            throw new \InvalidArgumentException(
+                sprintf(
+                    "Invalid value for 'outcomes', must be one of '%s'",
+                    implode("', '", $allowedValues)
+                )
+            );
+        }
+        $this->container['outcomes'] = $outcomes;
+
+        return $this;
+    }
+    /**
+     * Returns true if offset exists. False otherwise.
+     *
+     * @param integer $offset Offset
+     *
+     * @return boolean
+     */
+    public function offsetExists($offset): bool
+    {
+        return isset($this->container[$offset]);
+    }
+
+    /**
+     * Gets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return mixed|null
+     */
+    #[\ReturnTypeWillChange]
+    public function offsetGet($offset)
+    {
+        return $this->container[$offset] ?? null;
+    }
+
+    /**
+     * Sets value based on offset.
+     *
+     * @param int|null $offset Offset
+     * @param mixed    $value  Value to be set
+     *
+     * @return void
+     */
+    public function offsetSet($offset, $value): void
+    {
+        if (is_null($offset)) {
+            $this->container[] = $value;
+        } else {
+            $this->container[$offset] = $value;
+        }
+    }
+
+    /**
+     * Unsets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return void
+     */
+    public function offsetUnset($offset): void
+    {
+        unset($this->container[$offset]);
+    }
+
+    /**
+     * Serializes the object to a value that can be serialized natively by json_encode().
+     * @link https://www.php.net/manual/en/jsonserializable.jsonserialize.php
+     *
+     * @return mixed Returns data which can be serialized by json_encode(), which is a value
+     * of any type other than a resource.
+     */
+    #[\ReturnTypeWillChange]
+    public function jsonSerialize()
+    {
+       return ObjectSerializer::sanitizeForSerialization($this);
+    }
+
+    /**
+     * Gets the string presentation of the object
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return json_encode(
+            ObjectSerializer::sanitizeForSerialization($this),
+            JSON_PRETTY_PRINT
+        );
+    }
+
+    /**
+     * Gets a header-safe presentation of the object
+     *
+     * @return string
+     */
+    public function toHeaderValue()
+    {
+        return json_encode(ObjectSerializer::sanitizeForSerialization($this));
+    }
+}
+
+

samples/client/echo_api/php-nextgen/src/Model/StringEnumRef.php

@@ -0,0 +1,51 @@
+<?php
+/**
+ * StringEnumRef
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client\Model;
+use \OpenAPI\Client\ObjectSerializer;
+
+/**
+ * StringEnumRef Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+enum StringEnumRef: string
+{
+    case SUCCESS = 'success';
+
+    case FAILURE = 'failure';
+
+    case UNCLASSIFIED = 'unclassified';
+
+}
+
+

samples/client/echo_api/php-nextgen/src/Model/Tag.php

@@ -0,0 +1,444 @@
+<?php
+/**
+ * Tag
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client\Model;
+
+use \ArrayAccess;
+use \OpenAPI\Client\ObjectSerializer;
+
+/**
+ * Tag Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ * @implements \ArrayAccess<string, mixed>
+ */
+class Tag implements ModelInterface, ArrayAccess, \JsonSerializable
+{
+    public const DISCRIMINATOR = null;
+
+    /**
+      * The original name of the model.
+      *
+      * @var string
+      */
+    protected static $openAPIModelName = 'Tag';
+
+    /**
+      * Array of property to type mappings. Used for (de)serialization
+      *
+      * @var string[]
+      */
+    protected static $openAPITypes = [
+        'id' => 'int',
+        'name' => 'string'
+    ];
+
+    /**
+      * Array of property to format mappings. Used for (de)serialization
+      *
+      * @var string[]
+      * @phpstan-var array<string, string|null>
+      * @psalm-var array<string, string|null>
+      */
+    protected static $openAPIFormats = [
+        'id' => 'int64',
+        'name' => null
+    ];
+
+    /**
+      * Array of nullable properties. Used for (de)serialization
+      *
+      * @var boolean[]
+      */
+    protected static array $openAPINullables = [
+        'id' => false,
+		'name' => false
+    ];
+
+    /**
+      * If a nullable field gets set to null, insert it here
+      *
+      * @var boolean[]
+      */
+    protected array $openAPINullablesSetToNull = [];
+
+    /**
+     * Array of property to type mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPITypes()
+    {
+        return self::$openAPITypes;
+    }
+
+    /**
+     * Array of property to format mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPIFormats()
+    {
+        return self::$openAPIFormats;
+    }
+
+    /**
+     * Array of nullable properties
+     *
+     * @return array
+     */
+    protected static function openAPINullables(): array
+    {
+        return self::$openAPINullables;
+    }
+
+    /**
+     * Array of nullable field names deliberately set to null
+     *
+     * @return boolean[]
+     */
+    private function getOpenAPINullablesSetToNull(): array
+    {
+        return $this->openAPINullablesSetToNull;
+    }
+
+    /**
+     * Setter - Array of nullable field names deliberately set to null
+     *
+     * @param boolean[] $openAPINullablesSetToNull
+     */
+    private function setOpenAPINullablesSetToNull(array $openAPINullablesSetToNull): void
+    {
+        $this->openAPINullablesSetToNull = $openAPINullablesSetToNull;
+    }
+
+    /**
+     * Checks if a property is nullable
+     *
+     * @param string $property
+     * @return bool
+     */
+    public static function isNullable(string $property): bool
+    {
+        return self::openAPINullables()[$property] ?? false;
+    }
+
+    /**
+     * Checks if a nullable property is set to null.
+     *
+     * @param string $property
+     * @return bool
+     */
+    public function isNullableSetToNull(string $property): bool
+    {
+        return in_array($property, $this->getOpenAPINullablesSetToNull(), true);
+    }
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @var string[]
+     */
+    protected static $attributeMap = [
+        'id' => 'id',
+        'name' => 'name'
+    ];
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @var string[]
+     */
+    protected static $setters = [
+        'id' => 'setId',
+        'name' => 'setName'
+    ];
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @var string[]
+     */
+    protected static $getters = [
+        'id' => 'getId',
+        'name' => 'getName'
+    ];
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @return array
+     */
+    public static function attributeMap()
+    {
+        return self::$attributeMap;
+    }
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @return array
+     */
+    public static function setters()
+    {
+        return self::$setters;
+    }
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @return array
+     */
+    public static function getters()
+    {
+        return self::$getters;
+    }
+
+    /**
+     * The original name of the model.
+     *
+     * @return string
+     */
+    public function getModelName()
+    {
+        return self::$openAPIModelName;
+    }
+
+
+    /**
+     * Associative array for storing property values
+     *
+     * @var mixed[]
+     */
+    protected $container = [];
+
+    /**
+     * Constructor
+     *
+     * @param mixed[] $data Associated array of property values
+     *                      initializing the model
+     */
+    public function __construct(array $data = null)
+    {
+        $this->setIfExists('id', $data ?? [], null);
+        $this->setIfExists('name', $data ?? [], null);
+    }
+
+    /**
+    * Sets $this->container[$variableName] to the given data or to the given default Value; if $variableName
+    * is nullable and its value is set to null in the $fields array, then mark it as "set to null" in the
+    * $this->openAPINullablesSetToNull array
+    *
+    * @param string $variableName
+    * @param array  $fields
+    * @param mixed  $defaultValue
+    */
+    private function setIfExists(string $variableName, array $fields, $defaultValue): void
+    {
+        if (self::isNullable($variableName) && array_key_exists($variableName, $fields) && is_null($fields[$variableName])) {
+            $this->openAPINullablesSetToNull[] = $variableName;
+        }
+
+        $this->container[$variableName] = $fields[$variableName] ?? $defaultValue;
+    }
+
+    /**
+     * Show all the invalid properties with reasons.
+     *
+     * @return array invalid properties with reasons
+     */
+    public function listInvalidProperties()
+    {
+        $invalidProperties = [];
+
+        return $invalidProperties;
+    }
+
+    /**
+     * Validate all the properties in the model
+     * return true if all passed
+     *
+     * @return bool True if all properties are valid
+     */
+    public function valid()
+    {
+        return count($this->listInvalidProperties()) === 0;
+    }
+
+
+    /**
+     * Gets id
+     *
+     * @return int|null
+     */
+    public function getId()
+    {
+        return $this->container['id'];
+    }
+
+    /**
+     * Sets id
+     *
+     * @param int|null $id id
+     *
+     * @return self
+     */
+    public function setId($id)
+    {
+        if (is_null($id)) {
+            throw new \InvalidArgumentException('non-nullable id cannot be null');
+        }
+        $this->container['id'] = $id;
+
+        return $this;
+    }
+
+    /**
+     * Gets name
+     *
+     * @return string|null
+     */
+    public function getName()
+    {
+        return $this->container['name'];
+    }
+
+    /**
+     * Sets name
+     *
+     * @param string|null $name name
+     *
+     * @return self
+     */
+    public function setName($name)
+    {
+        if (is_null($name)) {
+            throw new \InvalidArgumentException('non-nullable name cannot be null');
+        }
+        $this->container['name'] = $name;
+
+        return $this;
+    }
+    /**
+     * Returns true if offset exists. False otherwise.
+     *
+     * @param integer $offset Offset
+     *
+     * @return boolean
+     */
+    public function offsetExists($offset): bool
+    {
+        return isset($this->container[$offset]);
+    }
+
+    /**
+     * Gets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return mixed|null
+     */
+    #[\ReturnTypeWillChange]
+    public function offsetGet($offset)
+    {
+        return $this->container[$offset] ?? null;
+    }
+
+    /**
+     * Sets value based on offset.
+     *
+     * @param int|null $offset Offset
+     * @param mixed    $value  Value to be set
+     *
+     * @return void
+     */
+    public function offsetSet($offset, $value): void
+    {
+        if (is_null($offset)) {
+            $this->container[] = $value;
+        } else {
+            $this->container[$offset] = $value;
+        }
+    }
+
+    /**
+     * Unsets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return void
+     */
+    public function offsetUnset($offset): void
+    {
+        unset($this->container[$offset]);
+    }
+
+    /**
+     * Serializes the object to a value that can be serialized natively by json_encode().
+     * @link https://www.php.net/manual/en/jsonserializable.jsonserialize.php
+     *
+     * @return mixed Returns data which can be serialized by json_encode(), which is a value
+     * of any type other than a resource.
+     */
+    #[\ReturnTypeWillChange]
+    public function jsonSerialize()
+    {
+       return ObjectSerializer::sanitizeForSerialization($this);
+    }
+
+    /**
+     * Gets the string presentation of the object
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return json_encode(
+            ObjectSerializer::sanitizeForSerialization($this),
+            JSON_PRETTY_PRINT
+        );
+    }
+
+    /**
+     * Gets a header-safe presentation of the object
+     *
+     * @return string
+     */
+    public function toHeaderValue()
+    {
+        return json_encode(ObjectSerializer::sanitizeForSerialization($this));
+    }
+}
+
+

samples/client/echo_api/php-nextgen/src/Model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter.php

@@ -0,0 +1,512 @@
+<?php
+/**
+ * TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client\Model;
+
+use \ArrayAccess;
+use \OpenAPI\Client\ObjectSerializer;
+
+/**
+ * TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ * @implements \ArrayAccess<string, mixed>
+ */
+class TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter implements ModelInterface, ArrayAccess, \JsonSerializable
+{
+    public const DISCRIMINATOR = null;
+
+    /**
+      * The original name of the model.
+      *
+      * @var string
+      */
+    protected static $openAPIModelName = 'test_query_style_deepObject_explode_true_object_allOf_query_object_parameter';
+
+    /**
+      * Array of property to type mappings. Used for (de)serialization
+      *
+      * @var string[]
+      */
+    protected static $openAPITypes = [
+        'size' => 'string',
+        'color' => 'string',
+        'id' => 'int',
+        'name' => 'string'
+    ];
+
+    /**
+      * Array of property to format mappings. Used for (de)serialization
+      *
+      * @var string[]
+      * @phpstan-var array<string, string|null>
+      * @psalm-var array<string, string|null>
+      */
+    protected static $openAPIFormats = [
+        'size' => null,
+        'color' => null,
+        'id' => 'int64',
+        'name' => null
+    ];
+
+    /**
+      * Array of nullable properties. Used for (de)serialization
+      *
+      * @var boolean[]
+      */
+    protected static array $openAPINullables = [
+        'size' => false,
+		'color' => false,
+		'id' => false,
+		'name' => false
+    ];
+
+    /**
+      * If a nullable field gets set to null, insert it here
+      *
+      * @var boolean[]
+      */
+    protected array $openAPINullablesSetToNull = [];
+
+    /**
+     * Array of property to type mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPITypes()
+    {
+        return self::$openAPITypes;
+    }
+
+    /**
+     * Array of property to format mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPIFormats()
+    {
+        return self::$openAPIFormats;
+    }
+
+    /**
+     * Array of nullable properties
+     *
+     * @return array
+     */
+    protected static function openAPINullables(): array
+    {
+        return self::$openAPINullables;
+    }
+
+    /**
+     * Array of nullable field names deliberately set to null
+     *
+     * @return boolean[]
+     */
+    private function getOpenAPINullablesSetToNull(): array
+    {
+        return $this->openAPINullablesSetToNull;
+    }
+
+    /**
+     * Setter - Array of nullable field names deliberately set to null
+     *
+     * @param boolean[] $openAPINullablesSetToNull
+     */
+    private function setOpenAPINullablesSetToNull(array $openAPINullablesSetToNull): void
+    {
+        $this->openAPINullablesSetToNull = $openAPINullablesSetToNull;
+    }
+
+    /**
+     * Checks if a property is nullable
+     *
+     * @param string $property
+     * @return bool
+     */
+    public static function isNullable(string $property): bool
+    {
+        return self::openAPINullables()[$property] ?? false;
+    }
+
+    /**
+     * Checks if a nullable property is set to null.
+     *
+     * @param string $property
+     * @return bool
+     */
+    public function isNullableSetToNull(string $property): bool
+    {
+        return in_array($property, $this->getOpenAPINullablesSetToNull(), true);
+    }
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @var string[]
+     */
+    protected static $attributeMap = [
+        'size' => 'size',
+        'color' => 'color',
+        'id' => 'id',
+        'name' => 'name'
+    ];
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @var string[]
+     */
+    protected static $setters = [
+        'size' => 'setSize',
+        'color' => 'setColor',
+        'id' => 'setId',
+        'name' => 'setName'
+    ];
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @var string[]
+     */
+    protected static $getters = [
+        'size' => 'getSize',
+        'color' => 'getColor',
+        'id' => 'getId',
+        'name' => 'getName'
+    ];
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @return array
+     */
+    public static function attributeMap()
+    {
+        return self::$attributeMap;
+    }
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @return array
+     */
+    public static function setters()
+    {
+        return self::$setters;
+    }
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @return array
+     */
+    public static function getters()
+    {
+        return self::$getters;
+    }
+
+    /**
+     * The original name of the model.
+     *
+     * @return string
+     */
+    public function getModelName()
+    {
+        return self::$openAPIModelName;
+    }
+
+
+    /**
+     * Associative array for storing property values
+     *
+     * @var mixed[]
+     */
+    protected $container = [];
+
+    /**
+     * Constructor
+     *
+     * @param mixed[] $data Associated array of property values
+     *                      initializing the model
+     */
+    public function __construct(array $data = null)
+    {
+        $this->setIfExists('size', $data ?? [], null);
+        $this->setIfExists('color', $data ?? [], null);
+        $this->setIfExists('id', $data ?? [], null);
+        $this->setIfExists('name', $data ?? [], null);
+    }
+
+    /**
+    * Sets $this->container[$variableName] to the given data or to the given default Value; if $variableName
+    * is nullable and its value is set to null in the $fields array, then mark it as "set to null" in the
+    * $this->openAPINullablesSetToNull array
+    *
+    * @param string $variableName
+    * @param array  $fields
+    * @param mixed  $defaultValue
+    */
+    private function setIfExists(string $variableName, array $fields, $defaultValue): void
+    {
+        if (self::isNullable($variableName) && array_key_exists($variableName, $fields) && is_null($fields[$variableName])) {
+            $this->openAPINullablesSetToNull[] = $variableName;
+        }
+
+        $this->container[$variableName] = $fields[$variableName] ?? $defaultValue;
+    }
+
+    /**
+     * Show all the invalid properties with reasons.
+     *
+     * @return array invalid properties with reasons
+     */
+    public function listInvalidProperties()
+    {
+        $invalidProperties = [];
+
+        return $invalidProperties;
+    }
+
+    /**
+     * Validate all the properties in the model
+     * return true if all passed
+     *
+     * @return bool True if all properties are valid
+     */
+    public function valid()
+    {
+        return count($this->listInvalidProperties()) === 0;
+    }
+
+
+    /**
+     * Gets size
+     *
+     * @return string|null
+     */
+    public function getSize()
+    {
+        return $this->container['size'];
+    }
+
+    /**
+     * Sets size
+     *
+     * @param string|null $size size
+     *
+     * @return self
+     */
+    public function setSize($size)
+    {
+        if (is_null($size)) {
+            throw new \InvalidArgumentException('non-nullable size cannot be null');
+        }
+        $this->container['size'] = $size;
+
+        return $this;
+    }
+
+    /**
+     * Gets color
+     *
+     * @return string|null
+     */
+    public function getColor()
+    {
+        return $this->container['color'];
+    }
+
+    /**
+     * Sets color
+     *
+     * @param string|null $color color
+     *
+     * @return self
+     */
+    public function setColor($color)
+    {
+        if (is_null($color)) {
+            throw new \InvalidArgumentException('non-nullable color cannot be null');
+        }
+        $this->container['color'] = $color;
+
+        return $this;
+    }
+
+    /**
+     * Gets id
+     *
+     * @return int|null
+     */
+    public function getId()
+    {
+        return $this->container['id'];
+    }
+
+    /**
+     * Sets id
+     *
+     * @param int|null $id id
+     *
+     * @return self
+     */
+    public function setId($id)
+    {
+        if (is_null($id)) {
+            throw new \InvalidArgumentException('non-nullable id cannot be null');
+        }
+        $this->container['id'] = $id;
+
+        return $this;
+    }
+
+    /**
+     * Gets name
+     *
+     * @return string|null
+     */
+    public function getName()
+    {
+        return $this->container['name'];
+    }
+
+    /**
+     * Sets name
+     *
+     * @param string|null $name name
+     *
+     * @return self
+     */
+    public function setName($name)
+    {
+        if (is_null($name)) {
+            throw new \InvalidArgumentException('non-nullable name cannot be null');
+        }
+        $this->container['name'] = $name;
+
+        return $this;
+    }
+    /**
+     * Returns true if offset exists. False otherwise.
+     *
+     * @param integer $offset Offset
+     *
+     * @return boolean
+     */
+    public function offsetExists($offset): bool
+    {
+        return isset($this->container[$offset]);
+    }
+
+    /**
+     * Gets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return mixed|null
+     */
+    #[\ReturnTypeWillChange]
+    public function offsetGet($offset)
+    {
+        return $this->container[$offset] ?? null;
+    }
+
+    /**
+     * Sets value based on offset.
+     *
+     * @param int|null $offset Offset
+     * @param mixed    $value  Value to be set
+     *
+     * @return void
+     */
+    public function offsetSet($offset, $value): void
+    {
+        if (is_null($offset)) {
+            $this->container[] = $value;
+        } else {
+            $this->container[$offset] = $value;
+        }
+    }
+
+    /**
+     * Unsets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return void
+     */
+    public function offsetUnset($offset): void
+    {
+        unset($this->container[$offset]);
+    }
+
+    /**
+     * Serializes the object to a value that can be serialized natively by json_encode().
+     * @link https://www.php.net/manual/en/jsonserializable.jsonserialize.php
+     *
+     * @return mixed Returns data which can be serialized by json_encode(), which is a value
+     * of any type other than a resource.
+     */
+    #[\ReturnTypeWillChange]
+    public function jsonSerialize()
+    {
+       return ObjectSerializer::sanitizeForSerialization($this);
+    }
+
+    /**
+     * Gets the string presentation of the object
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return json_encode(
+            ObjectSerializer::sanitizeForSerialization($this),
+            JSON_PRETTY_PRINT
+        );
+    }
+
+    /**
+     * Gets a header-safe presentation of the object
+     *
+     * @return string
+     */
+    public function toHeaderValue()
+    {
+        return json_encode(ObjectSerializer::sanitizeForSerialization($this));
+    }
+}
+
+

samples/client/echo_api/php-nextgen/src/Model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.php

@@ -0,0 +1,410 @@
+<?php
+/**
+ * TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client\Model;
+
+use \ArrayAccess;
+use \OpenAPI\Client\ObjectSerializer;
+
+/**
+ * TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ * @implements \ArrayAccess<string, mixed>
+ */
+class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter implements ModelInterface, ArrayAccess, \JsonSerializable
+{
+    public const DISCRIMINATOR = null;
+
+    /**
+      * The original name of the model.
+      *
+      * @var string
+      */
+    protected static $openAPIModelName = 'test_query_style_form_explode_true_array_string_query_object_parameter';
+
+    /**
+      * Array of property to type mappings. Used for (de)serialization
+      *
+      * @var string[]
+      */
+    protected static $openAPITypes = [
+        'values' => 'string[]'
+    ];
+
+    /**
+      * Array of property to format mappings. Used for (de)serialization
+      *
+      * @var string[]
+      * @phpstan-var array<string, string|null>
+      * @psalm-var array<string, string|null>
+      */
+    protected static $openAPIFormats = [
+        'values' => null
+    ];
+
+    /**
+      * Array of nullable properties. Used for (de)serialization
+      *
+      * @var boolean[]
+      */
+    protected static array $openAPINullables = [
+        'values' => false
+    ];
+
+    /**
+      * If a nullable field gets set to null, insert it here
+      *
+      * @var boolean[]
+      */
+    protected array $openAPINullablesSetToNull = [];
+
+    /**
+     * Array of property to type mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPITypes()
+    {
+        return self::$openAPITypes;
+    }
+
+    /**
+     * Array of property to format mappings. Used for (de)serialization
+     *
+     * @return array
+     */
+    public static function openAPIFormats()
+    {
+        return self::$openAPIFormats;
+    }
+
+    /**
+     * Array of nullable properties
+     *
+     * @return array
+     */
+    protected static function openAPINullables(): array
+    {
+        return self::$openAPINullables;
+    }
+
+    /**
+     * Array of nullable field names deliberately set to null
+     *
+     * @return boolean[]
+     */
+    private function getOpenAPINullablesSetToNull(): array
+    {
+        return $this->openAPINullablesSetToNull;
+    }
+
+    /**
+     * Setter - Array of nullable field names deliberately set to null
+     *
+     * @param boolean[] $openAPINullablesSetToNull
+     */
+    private function setOpenAPINullablesSetToNull(array $openAPINullablesSetToNull): void
+    {
+        $this->openAPINullablesSetToNull = $openAPINullablesSetToNull;
+    }
+
+    /**
+     * Checks if a property is nullable
+     *
+     * @param string $property
+     * @return bool
+     */
+    public static function isNullable(string $property): bool
+    {
+        return self::openAPINullables()[$property] ?? false;
+    }
+
+    /**
+     * Checks if a nullable property is set to null.
+     *
+     * @param string $property
+     * @return bool
+     */
+    public function isNullableSetToNull(string $property): bool
+    {
+        return in_array($property, $this->getOpenAPINullablesSetToNull(), true);
+    }
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @var string[]
+     */
+    protected static $attributeMap = [
+        'values' => 'values'
+    ];
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @var string[]
+     */
+    protected static $setters = [
+        'values' => 'setValues'
+    ];
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @var string[]
+     */
+    protected static $getters = [
+        'values' => 'getValues'
+    ];
+
+    /**
+     * Array of attributes where the key is the local name,
+     * and the value is the original name
+     *
+     * @return array
+     */
+    public static function attributeMap()
+    {
+        return self::$attributeMap;
+    }
+
+    /**
+     * Array of attributes to setter functions (for deserialization of responses)
+     *
+     * @return array
+     */
+    public static function setters()
+    {
+        return self::$setters;
+    }
+
+    /**
+     * Array of attributes to getter functions (for serialization of requests)
+     *
+     * @return array
+     */
+    public static function getters()
+    {
+        return self::$getters;
+    }
+
+    /**
+     * The original name of the model.
+     *
+     * @return string
+     */
+    public function getModelName()
+    {
+        return self::$openAPIModelName;
+    }
+
+
+    /**
+     * Associative array for storing property values
+     *
+     * @var mixed[]
+     */
+    protected $container = [];
+
+    /**
+     * Constructor
+     *
+     * @param mixed[] $data Associated array of property values
+     *                      initializing the model
+     */
+    public function __construct(array $data = null)
+    {
+        $this->setIfExists('values', $data ?? [], null);
+    }
+
+    /**
+    * Sets $this->container[$variableName] to the given data or to the given default Value; if $variableName
+    * is nullable and its value is set to null in the $fields array, then mark it as "set to null" in the
+    * $this->openAPINullablesSetToNull array
+    *
+    * @param string $variableName
+    * @param array  $fields
+    * @param mixed  $defaultValue
+    */
+    private function setIfExists(string $variableName, array $fields, $defaultValue): void
+    {
+        if (self::isNullable($variableName) && array_key_exists($variableName, $fields) && is_null($fields[$variableName])) {
+            $this->openAPINullablesSetToNull[] = $variableName;
+        }
+
+        $this->container[$variableName] = $fields[$variableName] ?? $defaultValue;
+    }
+
+    /**
+     * Show all the invalid properties with reasons.
+     *
+     * @return array invalid properties with reasons
+     */
+    public function listInvalidProperties()
+    {
+        $invalidProperties = [];
+
+        return $invalidProperties;
+    }
+
+    /**
+     * Validate all the properties in the model
+     * return true if all passed
+     *
+     * @return bool True if all properties are valid
+     */
+    public function valid()
+    {
+        return count($this->listInvalidProperties()) === 0;
+    }
+
+
+    /**
+     * Gets values
+     *
+     * @return string[]|null
+     */
+    public function getValues()
+    {
+        return $this->container['values'];
+    }
+
+    /**
+     * Sets values
+     *
+     * @param string[]|null $values values
+     *
+     * @return self
+     */
+    public function setValues($values)
+    {
+        if (is_null($values)) {
+            throw new \InvalidArgumentException('non-nullable values cannot be null');
+        }
+        $this->container['values'] = $values;
+
+        return $this;
+    }
+    /**
+     * Returns true if offset exists. False otherwise.
+     *
+     * @param integer $offset Offset
+     *
+     * @return boolean
+     */
+    public function offsetExists($offset): bool
+    {
+        return isset($this->container[$offset]);
+    }
+
+    /**
+     * Gets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return mixed|null
+     */
+    #[\ReturnTypeWillChange]
+    public function offsetGet($offset)
+    {
+        return $this->container[$offset] ?? null;
+    }
+
+    /**
+     * Sets value based on offset.
+     *
+     * @param int|null $offset Offset
+     * @param mixed    $value  Value to be set
+     *
+     * @return void
+     */
+    public function offsetSet($offset, $value): void
+    {
+        if (is_null($offset)) {
+            $this->container[] = $value;
+        } else {
+            $this->container[$offset] = $value;
+        }
+    }
+
+    /**
+     * Unsets offset.
+     *
+     * @param integer $offset Offset
+     *
+     * @return void
+     */
+    public function offsetUnset($offset): void
+    {
+        unset($this->container[$offset]);
+    }
+
+    /**
+     * Serializes the object to a value that can be serialized natively by json_encode().
+     * @link https://www.php.net/manual/en/jsonserializable.jsonserialize.php
+     *
+     * @return mixed Returns data which can be serialized by json_encode(), which is a value
+     * of any type other than a resource.
+     */
+    #[\ReturnTypeWillChange]
+    public function jsonSerialize()
+    {
+       return ObjectSerializer::sanitizeForSerialization($this);
+    }
+
+    /**
+     * Gets the string presentation of the object
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return json_encode(
+            ObjectSerializer::sanitizeForSerialization($this),
+            JSON_PRETTY_PRINT
+        );
+    }
+
+    /**
+     * Gets a header-safe presentation of the object
+     *
+     * @return string
+     */
+    public function toHeaderValue()
+    {
+        return json_encode(ObjectSerializer::sanitizeForSerialization($this));
+    }
+}
+
+

samples/client/echo_api/php-nextgen/src/ObjectSerializer.php

@@ -0,0 +1,567 @@
+<?php
+/**
+ * ObjectSerializer
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+namespace OpenAPI\Client;
+
+use GuzzleHttp\Psr7\Utils;
+use OpenAPI\Client\Model\ModelInterface;
+
+/**
+ * ObjectSerializer Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+class ObjectSerializer
+{
+    /** @var string */
+    private static $dateTimeFormat = \DateTime::ATOM;
+
+    /**
+     * Change the date format
+     *
+     * @param string $format   the new date format to use
+     */
+    public static function setDateTimeFormat($format)
+    {
+        self::$dateTimeFormat = $format;
+    }
+
+    /**
+     * Serialize data
+     *
+     * @param mixed  $data   the data to serialize
+     * @param string $type   the OpenAPIToolsType of the data
+     * @param string $format the format of the OpenAPITools type of the data
+     *
+     * @return scalar|object|array|null serialized form of $data
+     */
+    public static function sanitizeForSerialization($data, $type = null, $format = null)
+    {
+        if (is_scalar($data) || null === $data) {
+            return $data;
+        }
+
+        if ($data instanceof \DateTime) {
+            return ($format === 'date') ? $data->format('Y-m-d') : $data->format(self::$dateTimeFormat);
+        }
+
+        if (is_array($data)) {
+            foreach ($data as $property => $value) {
+                $data[$property] = self::sanitizeForSerialization($value);
+            }
+            return $data;
+        }
+
+        if (is_object($data)) {
+            $values = [];
+            if ($data instanceof ModelInterface) {
+                $formats = $data::openAPIFormats();
+                foreach ($data::openAPITypes() as $property => $openAPIType) {
+                    $getter = $data::getters()[$property];
+                    $value = $data->$getter();
+                    if ($value !== null && !in_array($openAPIType, ['\DateTime', '\SplFileObject', 'array', 'bool', 'boolean', 'byte', 'float', 'int', 'integer', 'mixed', 'number', 'object', 'string', 'void'], true)) {
+                        if (is_sublass_of($openAPIType, '\BackedEnum')) {
+                            $data = $openAPIType::tryFrom($data);
+                            if ($data === null) {
+                                $imploded = implode("', '", array_map(fn($case) => $case->value, $openAPIType::cases()));
+                                throw new \InvalidArgumentException("Invalid value for enum '$openAPIType', must be one of: '$imploded'");
+                            }
+                        }
+                    }
+                    if (($data::isNullable($property) && $data->isNullableSetToNull($property)) || $value !== null) {
+                        $values[$data::attributeMap()[$property]] = self::sanitizeForSerialization($value, $openAPIType, $formats[$property]);
+                    }
+                }
+            } else {
+                foreach($data as $property => $value) {
+                    $values[$property] = self::sanitizeForSerialization($value);
+                }
+            }
+            return (object)$values;
+        } else {
+            return (string)$data;
+        }
+    }
+
+    /**
+     * Sanitize filename by removing path.
+     * e.g. ../../sun.gif becomes sun.gif
+     *
+     * @param string $filename filename to be sanitized
+     *
+     * @return string the sanitized filename
+     */
+    public static function sanitizeFilename($filename)
+    {
+        if (preg_match("/.*[\/\\\\](.*)$/", $filename, $match)) {
+            return $match[1];
+        } else {
+            return $filename;
+        }
+    }
+
+    /**
+     * Shorter timestamp microseconds to 6 digits length.
+     *
+     * @param string $timestamp Original timestamp
+     *
+     * @return string the shorten timestamp
+     */
+    public static function sanitizeTimestamp($timestamp)
+    {
+        if (!is_string($timestamp)) return $timestamp;
+
+        return preg_replace('/(:\d{2}.\d{6})\d*/', '$1', $timestamp);
+    }
+
+    /**
+     * Take value and turn it into a string suitable for inclusion in
+     * the path, by url-encoding.
+     *
+     * @param string $value a string which will be part of the path
+     *
+     * @return string the serialized object
+     */
+    public static function toPathValue($value)
+    {
+        return rawurlencode(self::toString($value));
+    }
+
+    /**
+     * Checks if a value is empty, based on its OpenAPI type.
+     *
+     * @param mixed  $value
+     * @param string $openApiType
+     *
+     * @return bool true if $value is empty
+     */
+    private static function isEmptyValue($value, string $openApiType): bool
+    {
+        # If empty() returns false, it is not empty regardless of its type.
+        if (!empty($value)) {
+            return false;
+        }
+
+        # Null is always empty, as we cannot send a real "null" value in a query parameter.
+        if ($value === null) {
+            return true;
+        }
+
+        switch ($openApiType) {
+            # For numeric values, false and '' are considered empty.
+            # This comparison is safe for floating point values, since the previous call to empty() will
+            # filter out values that don't match 0.
+            case 'int':
+            case 'integer':
+                return $value !== 0;
+
+            case 'number':
+            case 'float':
+                return $value !== 0 && $value !== 0.0;
+
+            # For boolean values, '' is considered empty
+            case 'bool':
+            case 'boolean':
+                return !in_array($value, [false, 0], true);
+
+            # For all the other types, any value at this point can be considered empty.
+            default:
+                return true;
+        }
+    }
+
+    /**
+     * Take query parameter properties and turn it into an array suitable for
+     * native http_build_query or GuzzleHttp\Psr7\Query::build.
+     *
+     * @param mixed  $value       Parameter value
+     * @param string $paramName   Parameter name
+     * @param string $openApiType OpenAPIType eg. array or object
+     * @param string $style       Parameter serialization style
+     * @param bool   $explode     Parameter explode option
+     * @param bool   $required    Whether query param is required or not
+     *
+     * @return array
+     */
+    public static function toQueryValue(
+        $value,
+        string $paramName,
+        string $openApiType = 'string',
+        string $style = 'form',
+        bool $explode = true,
+        bool $required = true
+    ): array {
+
+        # Check if we should omit this parameter from the query. This should only happen when:
+        #  - Parameter is NOT required; AND
+        #  - its value is set to a value that is equivalent to "empty", depending on its OpenAPI type. For
+        #    example, 0 as "int" or "boolean" is NOT an empty value.
+        if (self::isEmptyValue($value, $openApiType)) {
+            if ($required) {
+                return ["{$paramName}" => ''];
+            } else {
+                return [];
+            }
+        }
+
+        # Handle DateTime objects in query
+        if($openApiType === "\\DateTime" && $value instanceof \DateTime) {
+            return ["{$paramName}" => $value->format(self::$dateTimeFormat)];
+        }
+
+        $query = [];
+        $value = (in_array($openApiType, ['object', 'array'], true)) ? (array)$value : $value;
+
+        // since \GuzzleHttp\Psr7\Query::build fails with nested arrays
+        // need to flatten array first
+        $flattenArray = function ($arr, $name, &$result = []) use (&$flattenArray, $style, $explode) {
+            if (!is_array($arr)) return $arr;
+
+            foreach ($arr as $k => $v) {
+                $prop = ($style === 'deepObject') ? $prop = "{$name}[{$k}]" : $k;
+
+                if (is_array($v)) {
+                    $flattenArray($v, $prop, $result);
+                } else {
+                    if ($style !== 'deepObject' && !$explode) {
+                        // push key itself
+                        $result[] = $prop;
+                    }
+                    $result[$prop] = $v;
+                }
+            }
+            return $result;
+        };
+
+        $value = $flattenArray($value, $paramName);
+
+        if ($openApiType === 'object' && ($style === 'deepObject' || $explode)) {
+            return $value;
+        }
+
+        if ('boolean' === $openApiType && is_bool($value)) {
+            $value = self::convertBoolToQueryStringFormat($value);
+        }
+
+        // handle style in serializeCollection
+        $query[$paramName] = ($explode) ? $value : self::serializeCollection((array)$value, $style);
+
+        return $query;
+    }
+
+    /**
+     * Convert boolean value to format for query string.
+     *
+     * @param bool $value Boolean value
+     *
+     * @return int|string Boolean value in format
+     */
+    public static function convertBoolToQueryStringFormat(bool $value)
+    {
+        if (Configuration::BOOLEAN_FORMAT_STRING == Configuration::getDefaultConfiguration()->getBooleanFormatForQueryString()) {
+            return $value ? 'true' : 'false';
+        }
+
+        return (int) $value;
+    }
+
+    /**
+     * Take value and turn it into a string suitable for inclusion in
+     * the header. If it's a string, pass through unchanged
+     * If it's a datetime object, format it in ISO8601
+     *
+     * @param string $value a string which will be part of the header
+     *
+     * @return string the header string
+     */
+    public static function toHeaderValue($value)
+    {
+        $callable = [$value, 'toHeaderValue'];
+        if (is_callable($callable)) {
+            return $callable();
+        }
+
+        return self::toString($value);
+    }
+
+    /**
+     * Take value and turn it into a string suitable for inclusion in
+     * the http body (form parameter). If it's a string, pass through unchanged
+     * If it's a datetime object, format it in ISO8601
+     *
+     * @param string|\SplFileObject $value the value of the form parameter
+     *
+     * @return string the form string
+     */
+    public static function toFormValue($value)
+    {
+        if ($value instanceof \SplFileObject) {
+            return $value->getRealPath();
+        } else {
+            return self::toString($value);
+        }
+    }
+
+    /**
+     * Take value and turn it into a string suitable for inclusion in
+     * the parameter. If it's a string, pass through unchanged
+     * If it's a datetime object, format it in ISO8601
+     * If it's a boolean, convert it to "true" or "false".
+     *
+     * @param string|bool|\DateTime $value the value of the parameter
+     *
+     * @return string the header string
+     */
+    public static function toString($value)
+    {
+        if ($value instanceof \DateTime) { // datetime in ISO8601 format
+            return $value->format(self::$dateTimeFormat);
+        } elseif (is_bool($value)) {
+            return $value ? 'true' : 'false';
+        } else {
+            return (string) $value;
+        }
+    }
+
+    /**
+     * Serialize an array to a string.
+     *
+     * @param array  $collection                 collection to serialize to a string
+     * @param string $style                      the format use for serialization (csv,
+     * ssv, tsv, pipes, multi)
+     * @param bool   $allowCollectionFormatMulti allow collection format to be a multidimensional array
+     *
+     * @return string
+     */
+    public static function serializeCollection(array $collection, $style, $allowCollectionFormatMulti = false)
+    {
+        if ($allowCollectionFormatMulti && ('multi' === $style)) {
+            // http_build_query() almost does the job for us. We just
+            // need to fix the result of multidimensional arrays.
+            return preg_replace('/%5B[0-9]+%5D=/', '=', http_build_query($collection, '', '&'));
+        }
+        switch ($style) {
+            case 'pipeDelimited':
+            case 'pipes':
+                return implode('|', $collection);
+
+            case 'tsv':
+                return implode("\t", $collection);
+
+            case 'spaceDelimited':
+            case 'ssv':
+                return implode(' ', $collection);
+
+            case 'simple':
+            case 'csv':
+                // Deliberate fall through. CSV is default format.
+            default:
+                return implode(',', $collection);
+        }
+    }
+
+    /**
+     * Deserialize a JSON string into an object
+     *
+     * @param mixed    $data          object or primitive to be deserialized
+     * @param string   $class         class name is passed as a string
+     * @param string[] $httpHeaders   HTTP headers
+     * @param string   $discriminator discriminator if polymorphism is used
+     *
+     * @return object|array|null a single or an array of $class instances
+     */
+    public static function deserialize($data, $class, $httpHeaders = null)
+    {
+        if (null === $data) {
+            return null;
+        }
+
+        if (strcasecmp(substr($class, -2), '[]') === 0) {
+            $data = is_string($data) ? json_decode($data) : $data;
+
+            if (!is_array($data)) {
+                throw new \InvalidArgumentException("Invalid array '$class'");
+            }
+
+            $subClass = substr($class, 0, -2);
+            $values = [];
+            foreach ($data as $key => $value) {
+                $values[] = self::deserialize($value, $subClass, null);
+            }
+            return $values;
+        }
+
+        if (preg_match('/^(array<|map\[)/', $class)) { // for associative array e.g. array<string,int>
+            $data = is_string($data) ? json_decode($data) : $data;
+            settype($data, 'array');
+            $inner = substr($class, 4, -1);
+            $deserialized = [];
+            if (strrpos($inner, ",") !== false) {
+                $subClass_array = explode(',', $inner, 2);
+                $subClass = $subClass_array[1];
+                foreach ($data as $key => $value) {
+                    $deserialized[$key] = self::deserialize($value, $subClass, null);
+                }
+            }
+            return $deserialized;
+        }
+
+        if ($class === 'object') {
+            settype($data, 'array');
+            return $data;
+        } elseif ($class === 'mixed') {
+            settype($data, gettype($data));
+            return $data;
+        }
+
+        if ($class === '\DateTime') {
+            // Some APIs return an invalid, empty string as a
+            // date-time property. DateTime::__construct() will return
+            // the current time for empty input which is probably not
+            // what is meant. The invalid empty string is probably to
+            // be interpreted as a missing field/value. Let's handle
+            // this graceful.
+            if (!empty($data)) {
+                try {
+                    return new \DateTime($data);
+                } catch (\Exception $exception) {
+                    // Some APIs return a date-time with too high nanosecond
+                    // precision for php's DateTime to handle.
+                    // With provided regexp 6 digits of microseconds saved
+                    return new \DateTime(self::sanitizeTimestamp($data));
+                }
+            } else {
+                return null;
+            }
+        }
+
+        if ($class === '\SplFileObject') {
+            $data = Utils::streamFor($data);
+
+            /** @var \Psr\Http\Message\StreamInterface $data */
+
+            // determine file name
+            if (
+                is_array($httpHeaders)
+                && array_key_exists('Content-Disposition', $httpHeaders) 
+                && preg_match('/inline; filename=[\'"]?([^\'"\s]+)[\'"]?$/i', $httpHeaders['Content-Disposition'], $match)
+            ) {
+                $filename = Configuration::getDefaultConfiguration()->getTempFolderPath() . DIRECTORY_SEPARATOR . self::sanitizeFilename($match[1]);
+            } else {
+                $filename = tempnam(Configuration::getDefaultConfiguration()->getTempFolderPath(), '');
+            }
+
+            $file = fopen($filename, 'w');
+            while ($chunk = $data->read(200)) {
+                fwrite($file, $chunk);
+            }
+            fclose($file);
+
+            return new \SplFileObject($filename, 'r');
+        }
+
+        /** @psalm-suppress ParadoxicalCondition */
+        if (in_array($class, ['\DateTime', '\SplFileObject', 'array', 'bool', 'boolean', 'byte', 'float', 'int', 'integer', 'mixed', 'number', 'object', 'string', 'void'], true)) {
+            settype($data, $class);
+            return $data;
+        }
+
+
+        if (is_subclass_of($class, '\BackedEnum')) {
+            $data = $class::tryFrom($data);
+            if ($data === null) {
+                $imploded = implode("', '", array_map(fn($case) => $case->value, $class::cases()));
+                throw new \InvalidArgumentException("Invalid value for enum '$class', must be one of: '$imploded'");
+            }
+            return $data;
+        } else {
+            $data = is_string($data) ? json_decode($data) : $data;
+
+            if (is_array($data)) {
+                $data = (object)$data;
+            }
+
+            // If a discriminator is defined and points to a valid subclass, use it.
+            $discriminator = $class::DISCRIMINATOR;
+            if (!empty($discriminator) && isset($data->{$discriminator}) && is_string($data->{$discriminator})) {
+                $subclass = '\OpenAPI\Client\Model\\' . $data->{$discriminator};
+                if (is_subclass_of($subclass, $class)) {
+                    $class = $subclass;
+                }
+            }
+
+            /** @var ModelInterface $instance */
+            $instance = new $class();
+            foreach ($instance::openAPITypes() as $property => $type) {
+                $propertySetter = $instance::setters()[$property];
+
+                if (!isset($propertySetter)) {
+                    continue;
+                }
+
+                if (!isset($data->{$instance::attributeMap()[$property]})) {
+                    if ($instance::isNullable($property)) {
+                        $instance->$propertySetter(null);
+                    }
+
+                    continue;
+                }
+
+                if (isset($data->{$instance::attributeMap()[$property]})) {
+                    $propertyValue = $data->{$instance::attributeMap()[$property]};
+                    $instance->$propertySetter(self::deserialize($propertyValue, $type, null));
+                }
+            }
+            return $instance;
+        }
+    }
+
+    /**
+     * Native `http_build_query` wrapper.
+     * @see https://www.php.net/manual/en/function.http-build-query
+     *
+     * @param array|object $data           May be an array or object containing properties.
+     * @param string       $numeric_prefix If numeric indices are used in the base array and this parameter is provided, it will be prepended to the numeric index for elements in the base array only.
+     * @param string|null  $arg_separator  arg_separator.output is used to separate arguments but may be overridden by specifying this parameter.
+     * @param int          $encoding_type  Encoding type. By default, PHP_QUERY_RFC1738.
+     *
+     * @return string
+     */
+    public static function buildQuery(
+        $data,
+        string $numeric_prefix = '',
+        ?string $arg_separator = null,
+        int $encoding_type = \PHP_QUERY_RFC3986
+    ): string {
+        return \GuzzleHttp\Psr7\Query::build($data, $encoding_type);
+    }
+}

samples/client/echo_api/php-nextgen/tests/Api/AuthApiTest.php

@@ -0,0 +1,86 @@
+<?php
+/**
+ * AuthApiTest
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the endpoint.
+ */
+
+namespace OpenAPI\Client\Test\Api;
+
+use \OpenAPI\Client\Configuration;
+use \OpenAPI\Client\ApiException;
+use \OpenAPI\Client\ObjectSerializer;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * AuthApiTest Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+class AuthApiTest extends TestCase
+{
+
+    /**
+     * Setup before running any test cases
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test case for testAuthHttpBasic
+     *
+     * To test HTTP basic authentication.
+     *
+     */
+    public function testTestAuthHttpBasic()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}

samples/client/echo_api/php-nextgen/tests/Api/BodyApiTest.php

@@ -0,0 +1,158 @@
+<?php
+/**
+ * BodyApiTest
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the endpoint.
+ */
+
+namespace OpenAPI\Client\Test\Api;
+
+use \OpenAPI\Client\Configuration;
+use \OpenAPI\Client\ApiException;
+use \OpenAPI\Client\ObjectSerializer;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * BodyApiTest Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+class BodyApiTest extends TestCase
+{
+
+    /**
+     * Setup before running any test cases
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test case for testBinaryGif
+     *
+     * Test binary (gif) response body.
+     *
+     */
+    public function testTestBinaryGif()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test case for testBodyApplicationOctetstreamBinary
+     *
+     * Test body parameter(s).
+     *
+     */
+    public function testTestBodyApplicationOctetstreamBinary()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test case for testBodyMultipartFormdataArrayOfBinary
+     *
+     * Test array of binary in multipart mime.
+     *
+     */
+    public function testTestBodyMultipartFormdataArrayOfBinary()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test case for testEchoBodyFreeFormObjectResponseString
+     *
+     * Test free form object.
+     *
+     */
+    public function testTestEchoBodyFreeFormObjectResponseString()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test case for testEchoBodyPet
+     *
+     * Test body parameter(s).
+     *
+     */
+    public function testTestEchoBodyPet()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test case for testEchoBodyPetResponseString
+     *
+     * Test empty response body.
+     *
+     */
+    public function testTestEchoBodyPetResponseString()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test case for testEchoBodyTagResponseString
+     *
+     * Test empty json (request body).
+     *
+     */
+    public function testTestEchoBodyTagResponseString()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}

samples/client/echo_api/php-nextgen/tests/Api/FormApiTest.php

@@ -0,0 +1,98 @@
+<?php
+/**
+ * FormApiTest
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the endpoint.
+ */
+
+namespace OpenAPI\Client\Test\Api;
+
+use \OpenAPI\Client\Configuration;
+use \OpenAPI\Client\ApiException;
+use \OpenAPI\Client\ObjectSerializer;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * FormApiTest Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+class FormApiTest extends TestCase
+{
+
+    /**
+     * Setup before running any test cases
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test case for testFormIntegerBooleanString
+     *
+     * Test form parameter(s).
+     *
+     */
+    public function testTestFormIntegerBooleanString()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test case for testFormOneof
+     *
+     * Test form parameter(s) for oneOf schema.
+     *
+     */
+    public function testTestFormOneof()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}

samples/client/echo_api/php-nextgen/tests/Api/HeaderApiTest.php

@@ -0,0 +1,86 @@
+<?php
+/**
+ * HeaderApiTest
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the endpoint.
+ */
+
+namespace OpenAPI\Client\Test\Api;
+
+use \OpenAPI\Client\Configuration;
+use \OpenAPI\Client\ApiException;
+use \OpenAPI\Client\ObjectSerializer;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * HeaderApiTest Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+class HeaderApiTest extends TestCase
+{
+
+    /**
+     * Setup before running any test cases
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test case for testHeaderIntegerBooleanString
+     *
+     * Test header parameter(s).
+     *
+     */
+    public function testTestHeaderIntegerBooleanString()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}

samples/client/echo_api/php-nextgen/tests/Api/PathApiTest.php

@@ -0,0 +1,86 @@
+<?php
+/**
+ * PathApiTest
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the endpoint.
+ */
+
+namespace OpenAPI\Client\Test\Api;
+
+use \OpenAPI\Client\Configuration;
+use \OpenAPI\Client\ApiException;
+use \OpenAPI\Client\ObjectSerializer;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * PathApiTest Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+class PathApiTest extends TestCase
+{
+
+    /**
+     * Setup before running any test cases
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test case for testsPathStringPathStringIntegerPathInteger
+     *
+     * Test path parameter(s).
+     *
+     */
+    public function testTestsPathStringPathStringIntegerPathInteger()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}

samples/client/echo_api/php-nextgen/tests/Api/QueryApiTest.php

@@ -0,0 +1,170 @@
+<?php
+/**
+ * QueryApiTest
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the endpoint.
+ */
+
+namespace OpenAPI\Client\Test\Api;
+
+use \OpenAPI\Client\Configuration;
+use \OpenAPI\Client\ApiException;
+use \OpenAPI\Client\ObjectSerializer;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * QueryApiTest Class Doc Comment
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+class QueryApiTest extends TestCase
+{
+
+    /**
+     * Setup before running any test cases
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test case for testEnumRefString
+     *
+     * Test query parameter(s).
+     *
+     */
+    public function testTestEnumRefString()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test case for testQueryDatetimeDateString
+     *
+     * Test query parameter(s).
+     *
+     */
+    public function testTestQueryDatetimeDateString()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test case for testQueryIntegerBooleanString
+     *
+     * Test query parameter(s).
+     *
+     */
+    public function testTestQueryIntegerBooleanString()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test case for testQueryStyleDeepObjectExplodeTrueObject
+     *
+     * Test query parameter(s).
+     *
+     */
+    public function testTestQueryStyleDeepObjectExplodeTrueObject()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test case for testQueryStyleDeepObjectExplodeTrueObjectAllOf
+     *
+     * Test query parameter(s).
+     *
+     */
+    public function testTestQueryStyleDeepObjectExplodeTrueObjectAllOf()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test case for testQueryStyleFormExplodeTrueArrayString
+     *
+     * Test query parameter(s).
+     *
+     */
+    public function testTestQueryStyleFormExplodeTrueArrayString()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test case for testQueryStyleFormExplodeTrueObject
+     *
+     * Test query parameter(s).
+     *
+     */
+    public function testTestQueryStyleFormExplodeTrueObject()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test case for testQueryStyleFormExplodeTrueObjectAllOf
+     *
+     * Test query parameter(s).
+     *
+     */
+    public function testTestQueryStyleFormExplodeTrueObjectAllOf()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}

samples/client/echo_api/php-nextgen/tests/Model/BirdTest.php

@@ -0,0 +1,100 @@
+<?php
+/**
+ * BirdTest
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the model.
+ */
+
+namespace OpenAPI\Client\Test\Model;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * BirdTest Class Doc Comment
+ *
+ * @category    Class
+ * @description Bird
+ * @package     OpenAPI\Client
+ * @author      OpenAPI Generator team
+ * @link        https://openapi-generator.tech
+ */
+class BirdTest extends TestCase
+{
+
+    /**
+     * Setup before running any test case
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test "Bird"
+     */
+    public function testBird()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "size"
+     */
+    public function testPropertySize()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "color"
+     */
+    public function testPropertyColor()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}

samples/client/echo_api/php-nextgen/tests/Model/CategoryTest.php

@@ -0,0 +1,100 @@
+<?php
+/**
+ * CategoryTest
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the model.
+ */
+
+namespace OpenAPI\Client\Test\Model;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * CategoryTest Class Doc Comment
+ *
+ * @category    Class
+ * @description Category
+ * @package     OpenAPI\Client
+ * @author      OpenAPI Generator team
+ * @link        https://openapi-generator.tech
+ */
+class CategoryTest extends TestCase
+{
+
+    /**
+     * Setup before running any test case
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test "Category"
+     */
+    public function testCategory()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "id"
+     */
+    public function testPropertyId()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "name"
+     */
+    public function testPropertyName()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}

samples/client/echo_api/php-nextgen/tests/Model/DataQueryTest.php

@@ -0,0 +1,109 @@
+<?php
+/**
+ * DataQueryTest
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the model.
+ */
+
+namespace OpenAPI\Client\Test\Model;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * DataQueryTest Class Doc Comment
+ *
+ * @category    Class
+ * @description DataQuery
+ * @package     OpenAPI\Client
+ * @author      OpenAPI Generator team
+ * @link        https://openapi-generator.tech
+ */
+class DataQueryTest extends TestCase
+{
+
+    /**
+     * Setup before running any test case
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test "DataQuery"
+     */
+    public function testDataQuery()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "suffix"
+     */
+    public function testPropertySuffix()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "text"
+     */
+    public function testPropertyText()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "date"
+     */
+    public function testPropertyDate()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}

samples/client/echo_api/php-nextgen/tests/Model/DefaultValueTest.php

@@ -0,0 +1,154 @@
+<?php
+/**
+ * DefaultValueTest
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the model.
+ */
+
+namespace OpenAPI\Client\Test\Model;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * DefaultValueTest Class Doc Comment
+ *
+ * @category    Class
+ * @description to test the default value of properties
+ * @package     OpenAPI\Client
+ * @author      OpenAPI Generator team
+ * @link        https://openapi-generator.tech
+ */
+class DefaultValueTest extends TestCase
+{
+
+    /**
+     * Setup before running any test case
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test "DefaultValue"
+     */
+    public function testDefaultValue()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "array_string_enum_ref_default"
+     */
+    public function testPropertyArrayStringEnumRefDefault()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "array_string_enum_default"
+     */
+    public function testPropertyArrayStringEnumDefault()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "array_string_default"
+     */
+    public function testPropertyArrayStringDefault()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "array_integer_default"
+     */
+    public function testPropertyArrayIntegerDefault()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "array_string"
+     */
+    public function testPropertyArrayString()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "array_string_nullable"
+     */
+    public function testPropertyArrayStringNullable()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "array_string_extension_nullable"
+     */
+    public function testPropertyArrayStringExtensionNullable()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "string_nullable"
+     */
+    public function testPropertyStringNullable()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}

samples/client/echo_api/php-nextgen/tests/Model/NumberPropertiesOnlyTest.php

@@ -0,0 +1,109 @@
+<?php
+/**
+ * NumberPropertiesOnlyTest
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the model.
+ */
+
+namespace OpenAPI\Client\Test\Model;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * NumberPropertiesOnlyTest Class Doc Comment
+ *
+ * @category    Class
+ * @description NumberPropertiesOnly
+ * @package     OpenAPI\Client
+ * @author      OpenAPI Generator team
+ * @link        https://openapi-generator.tech
+ */
+class NumberPropertiesOnlyTest extends TestCase
+{
+
+    /**
+     * Setup before running any test case
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test "NumberPropertiesOnly"
+     */
+    public function testNumberPropertiesOnly()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "number"
+     */
+    public function testPropertyNumber()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "float"
+     */
+    public function testPropertyFloat()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "double"
+     */
+    public function testPropertyDouble()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}

samples/client/echo_api/php-nextgen/tests/Model/PetTest.php

@@ -0,0 +1,136 @@
+<?php
+/**
+ * PetTest
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the model.
+ */
+
+namespace OpenAPI\Client\Test\Model;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * PetTest Class Doc Comment
+ *
+ * @category    Class
+ * @description Pet
+ * @package     OpenAPI\Client
+ * @author      OpenAPI Generator team
+ * @link        https://openapi-generator.tech
+ */
+class PetTest extends TestCase
+{
+
+    /**
+     * Setup before running any test case
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test "Pet"
+     */
+    public function testPet()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "id"
+     */
+    public function testPropertyId()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "name"
+     */
+    public function testPropertyName()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "category"
+     */
+    public function testPropertyCategory()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "photo_urls"
+     */
+    public function testPropertyPhotoUrls()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "tags"
+     */
+    public function testPropertyTags()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "status"
+     */
+    public function testPropertyStatus()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}

samples/client/echo_api/php-nextgen/tests/Model/QueryTest.php

@@ -0,0 +1,100 @@
+<?php
+/**
+ * QueryTest
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the model.
+ */
+
+namespace OpenAPI\Client\Test\Model;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * QueryTest Class Doc Comment
+ *
+ * @category    Class
+ * @description Query
+ * @package     OpenAPI\Client
+ * @author      OpenAPI Generator team
+ * @link        https://openapi-generator.tech
+ */
+class QueryTest extends TestCase
+{
+
+    /**
+     * Setup before running any test case
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test "Query"
+     */
+    public function testQuery()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "id"
+     */
+    public function testPropertyId()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "outcomes"
+     */
+    public function testPropertyOutcomes()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}

samples/client/echo_api/php-nextgen/tests/Model/StringEnumRefTest.php

@@ -0,0 +1,82 @@
+<?php
+/**
+ * StringEnumRefTest
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the model.
+ */
+
+namespace OpenAPI\Client\Test\Model;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * StringEnumRefTest Class Doc Comment
+ *
+ * @category    Class
+ * @description StringEnumRef
+ * @package     OpenAPI\Client
+ * @author      OpenAPI Generator team
+ * @link        https://openapi-generator.tech
+ */
+class StringEnumRefTest extends TestCase
+{
+
+    /**
+     * Setup before running any test case
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test "StringEnumRef"
+     */
+    public function testStringEnumRef()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}

samples/client/echo_api/php-nextgen/tests/Model/TagTest.php

@@ -0,0 +1,100 @@
+<?php
+/**
+ * TagTest
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the model.
+ */
+
+namespace OpenAPI\Client\Test\Model;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * TagTest Class Doc Comment
+ *
+ * @category    Class
+ * @description Tag
+ * @package     OpenAPI\Client
+ * @author      OpenAPI Generator team
+ * @link        https://openapi-generator.tech
+ */
+class TagTest extends TestCase
+{
+
+    /**
+     * Setup before running any test case
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test "Tag"
+     */
+    public function testTag()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "id"
+     */
+    public function testPropertyId()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "name"
+     */
+    public function testPropertyName()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}

samples/client/echo_api/php-nextgen/tests/Model/TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameterTest.php

@@ -0,0 +1,118 @@
+<?php
+/**
+ * TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameterTest
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the model.
+ */
+
+namespace OpenAPI\Client\Test\Model;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameterTest Class Doc Comment
+ *
+ * @category    Class
+ * @description TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter
+ * @package     OpenAPI\Client
+ * @author      OpenAPI Generator team
+ * @link        https://openapi-generator.tech
+ */
+class TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameterTest extends TestCase
+{
+
+    /**
+     * Setup before running any test case
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test "TestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter"
+     */
+    public function testTestQueryStyleDeepObjectExplodeTrueObjectAllOfQueryObjectParameter()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "size"
+     */
+    public function testPropertySize()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "color"
+     */
+    public function testPropertyColor()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "id"
+     */
+    public function testPropertyId()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "name"
+     */
+    public function testPropertyName()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}

samples/client/echo_api/php-nextgen/tests/Model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameterTest.php

@@ -0,0 +1,91 @@
+<?php
+/**
+ * TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameterTest
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OpenAPI\Client
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * Echo Server API
+ *
+ * Echo Server API
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * Contact: team@openapitools.org
+ * @generated Generated by: https://openapi-generator.tech
+ * OpenAPI Generator version: 7.0.1-SNAPSHOT
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the model.
+ */
+
+namespace OpenAPI\Client\Test\Model;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameterTest Class Doc Comment
+ *
+ * @category    Class
+ * @description TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter
+ * @package     OpenAPI\Client
+ * @author      OpenAPI Generator team
+ * @link        https://openapi-generator.tech
+ */
+class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameterTest extends TestCase
+{
+
+    /**
+     * Setup before running any test case
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test "TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter"
+     */
+    public function testTestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+
+    /**
+     * Test attribute "values"
+     */
+    public function testPropertyValues()
+    {
+        // TODO: implement
+        $this->markTestIncomplete('Not implemented');
+    }
+}