use map/array model class only if it is generated (#17612)

* fix

* tests

* generate samples

* refactor

samples/client/petstore/javascript-es6/src/api/FakeApi.js

@@ -934,5 +934,46 @@ export default class FakeApi {
       );
     }
 
+    /**
+     * Callback function to receive the result of the testStringMapReference operation.
+     * @callback module:api/FakeApi~testStringMapReferenceCallback
+     * @param {String} error Error message, if any.
+     * @param data This operation does not return a value.
+     * @param {String} response The complete HTTP response.
+     */
+
+    /**
+     * test referenced string map
+     * 
+     * @param {Object.<String, {String: String}>} requestBody request body
+     * @param {module:api/FakeApi~testStringMapReferenceCallback} callback The callback function, accepting three arguments: error, data, response
+     */
+    testStringMapReference(requestBody, callback) {
+      let postBody = requestBody;
+      // verify the required parameter 'requestBody' is set
+      if (requestBody === undefined || requestBody === null) {
+        throw new Error("Missing the required parameter 'requestBody' when calling testStringMapReference");
+      }
+
+      let pathParams = {
+      };
+      let queryParams = {
+      };
+      let headerParams = {
+      };
+      let formParams = {
+      };
+
+      let authNames = [];
+      let contentTypes = ['application/json'];
+      let accepts = [];
+      let returnType = null;
+      return this.apiClient.callApi(
+        '/fake/stringMap-reference', 'POST',
+        pathParams, queryParams, headerParams, formParams, postBody,
+        authNames, contentTypes, accepts, returnType, null, callback
+      );
+    }
+
 
 }