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/java/resttemplate-withXml/docs/ChildWithNullable.md

@@ -0,0 +1,13 @@
+
+
+# ChildWithNullable
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**otherProperty** | **String** |  |  [optional] |
+
+
+

samples/client/petstore/java/resttemplate-withXml/docs/FakeApi.md

@@ -21,6 +21,7 @@ All URIs are relative to *http://petstore.swagger.io:80/v2*
 | [**testGroupParameters**](FakeApi.md#testGroupParameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional) |
 | [**testInlineAdditionalProperties**](FakeApi.md#testInlineAdditionalProperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties |
 | [**testJsonFormData**](FakeApi.md#testJsonFormData) | **GET** /fake/jsonFormData | test json serialization of form data |
+| [**testNullable**](FakeApi.md#testNullable) | **POST** /fake/nullable | test nullable parent property |
 | [**testQueryParameterCollectionFormat**](FakeApi.md#testQueryParameterCollectionFormat) | **PUT** /fake/test-query-parameters |  |
 
 
@@ -1199,6 +1200,71 @@ No authorization required
 | **200** | successful operation |  -  |
 
 
+## testNullable
+
+> testNullable(childWithNullable)
+
+test nullable parent property
+
+
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.FakeApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+
+        FakeApi apiInstance = new FakeApi(defaultClient);
+        ChildWithNullable childWithNullable = new ChildWithNullable(); // ChildWithNullable | request body
+        try {
+            apiInstance.testNullable(childWithNullable);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling FakeApi#testNullable");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+| Name | Type | Description  | Notes |
+|------------- | ------------- | ------------- | -------------|
+| **childWithNullable** | [**ChildWithNullable**](ChildWithNullable.md)| request body | |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: application/json
+- **Accept**: Not defined
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+
+
 ## testQueryParameterCollectionFormat
 
 > testQueryParameterCollectionFormat(pipe, ioutil, http, url, context, allowEmpty, language)

samples/client/petstore/java/resttemplate-withXml/docs/ParentWithNullable.md

@@ -0,0 +1,22 @@
+
+
+# ParentWithNullable
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**type** | [**TypeEnum**](#TypeEnum) |  |  [optional] |
+|**nullableProperty** | **String** |  |  [optional] |
+
+
+
+## Enum: TypeEnum
+
+| Name | Value |
+|---- | -----|
+| CHILDWITHNULLABLE | "ChildWithNullable" |
+
+
+