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