code: protected HttpContext service(HttpRequest request, HttpResponse response)
          throws HttpException, IOException
      {
          if (_httpServer==null)
                  throw new HttpException(HttpResponse.__503_Service_Unavailable);
          return _httpServer.service(request,response);
      }
docs: Service a Request.
  This implementation passes the request and response to the
  service method of the HttpServer for this connections listener.
  If no HttpServer has been associated, the 503 is returned.
  This method may be specialized to implement other ways of
  servicing a request.
  @param request The request
  @param response The response
  @return The HttpContext that completed handling of the request or null.
  @exception HttpException
  @exception IOException