code: func HTTPRespondMarshalXML(response interface{}, rootElement string, responseWriter http.ResponseWriter, request *http.Request) (err error) {
  	NewHTTPCompressHandlerFromFunc(func(responseWriter http.ResponseWriter, request *http.Request) {
  		var data []byte
  		if data, err = xml.Marshal(response); err == nil {
  			responseWriter.Header().Set("Content-Type", "application/xml")
  			if rootElement == "" {
  				_, err = fmt.Fprintf(responseWriter, "%s%s", xml.Header, data)
  			} else {
  				_, err = fmt.Fprintf(responseWriter, "%s<%s>%s</%s>", xml.Header, rootElement, data, rootElement)
  			}
  		}
  	}).ServeHTTP(responseWriter, request)
  	return err
  }
docs: // HTTPRespondMarshalXML marshals response as XML to responseWriter, sets Content-Type to application/xml
  // and compresses the response if Content-Encoding from the request allows it.
  // If rootElement is not empty, then an additional root element with this name will be wrapped around the content.