code: public static void sendDevTimeError( String messageKey, Throwable cause, int productionTimeErrorCode,
                                           ServletRequest request, ServletResponse response,
                                           ServletContext servletContext, Object[] messageArgs )
              throws IOException
      {
          sendDevTimeError( messageKey, messageArgs, cause, productionTimeErrorCode, request, response, servletContext );
      }
docs: If not in production mode, write an error to the response; otherwise, set a response error code.