add test case for nullable parent property (#16552)

* add nullable case to spring test spec

* generate samples for changed spring input

* add nullable case to general test spec

* generate samples for changed general input

* generate samples again

* generates samples again

* re-build from new sources, generates samples again

samples/client/petstore/ruby-autoload/docs/ChildWithNullable.md

@@ -0,0 +1,18 @@
+# Petstore::ChildWithNullable
+
+## Properties
+
+| Name | Type | Description | Notes |
+| ---- | ---- | ----------- | ----- |
+| **other_property** | **String** |  | [optional] |
+
+## Example
+
+```ruby
+require 'petstore'
+
+instance = Petstore::ChildWithNullable.new(
+  other_property: null
+)
+```
+

samples/client/petstore/ruby-autoload/docs/FakeApi.md

@@ -21,6 +21,7 @@ All URIs are relative to *http://petstore.swagger.io:80/v2*
 | [**test_group_parameters**](FakeApi.md#test_group_parameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional) |
 | [**test_inline_additional_properties**](FakeApi.md#test_inline_additional_properties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties |
 | [**test_json_form_data**](FakeApi.md#test_json_form_data) | **GET** /fake/jsonFormData | test json serialization of form data |
+| [**test_nullable**](FakeApi.md#test_nullable) | **POST** /fake/nullable | test nullable parent property |
 | [**test_query_parameter_collection_format**](FakeApi.md#test_query_parameter_collection_format) | **PUT** /fake/test-query-parameters |  |
 
 
@@ -1181,6 +1182,69 @@ No authorization required
 - **Accept**: Not defined
 
 
+## test_nullable
+
+> test_nullable(child_with_nullable)
+
+test nullable parent property
+
+
+
+### Examples
+
+```ruby
+require 'time'
+require 'petstore'
+
+api_instance = Petstore::FakeApi.new
+child_with_nullable = Petstore::ChildWithNullable.new # ChildWithNullable | request body
+
+begin
+  # test nullable parent property
+  api_instance.test_nullable(child_with_nullable)
+rescue Petstore::ApiError => e
+  puts "Error when calling FakeApi->test_nullable: #{e}"
+end
+```
+
+#### Using the test_nullable_with_http_info variant
+
+This returns an Array which contains the response data (`nil` in this case), status code and headers.
+
+> <Array(nil, Integer, Hash)> test_nullable_with_http_info(child_with_nullable)
+
+```ruby
+begin
+  # test nullable parent property
+  data, status_code, headers = api_instance.test_nullable_with_http_info(child_with_nullable)
+  p status_code # => 2xx
+  p headers # => { ... }
+  p data # => nil
+rescue Petstore::ApiError => e
+  puts "Error when calling FakeApi->test_nullable_with_http_info: #{e}"
+end
+```
+
+### Parameters
+
+| Name | Type | Description | Notes |
+| ---- | ---- | ----------- | ----- |
+| **child_with_nullable** | [**ChildWithNullable**](ChildWithNullable.md) | request body |  |
+
+### Return type
+
+nil (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: application/json
+- **Accept**: Not defined
+
+
 ## test_query_parameter_collection_format
 
 > test_query_parameter_collection_format(pipe, ioutil, http, url, context, allow_empty, opts)

samples/client/petstore/ruby-autoload/docs/ParentWithNullable.md

@@ -0,0 +1,20 @@
+# Petstore::ParentWithNullable
+
+## Properties
+
+| Name | Type | Description | Notes |
+| ---- | ---- | ----------- | ----- |
+| **type** | **String** |  | [optional] |
+| **nullable_property** | **String** |  | [optional] |
+
+## Example
+
+```ruby
+require 'petstore'
+
+instance = Petstore::ParentWithNullable.new(
+  type: null,
+  nullable_property: null
+)
+```
+