code: func (r *Reader) Copy(w http.ResponseWriter, req *http.Request) error {
  	go func() {
  		defer util.HandleCrash()
  		websocket.Server{Handshake: r.handshake, Handler: r.handle}.ServeHTTP(w, req)
  	}()
  	return <-r.err
  }
docs: // Copy the reader to the response. The created WebSocket is closed after this
  // method completes.