code: void sendError( ServletRequest request, ServletResponse response, ServletContext servletContext,
                      int productionTimeErrorCode )
          throws IOException
      {
          InternalUtils.sendDevTimeError( _messageKeyPrefix, getMessageArgs(), null, productionTimeErrorCode,
                                          request, response, servletContext );
      }
docs: Handle the error by writing a message to the response.
  
  @param request the current HttpServletRequest
  @param response the current HttpServletResponse