code: public static DefaultGoApiResponse error(String responseBody) {
          DefaultGoApiResponse defaultGoApiResponse = new DefaultGoApiResponse(500);
          defaultGoApiResponse.setResponseBody(responseBody);
          return defaultGoApiResponse;
      }
docs: Creates an instance DefaultGoApiResponse which represents error request with response code 500
  
  @param responseBody Response body
  @return an instance of DefaultGoApiResponse