code: func (h *portForwardProxy) monitorStreamPair(p *httpStreamPair, timeout <-chan time.Time) {
  	select {
  	case <-timeout:
  		err := fmt.Errorf("(conn=%v, request=%s) timed out waiting for streams", h.sourceConn, p.requestID)
  		p.printError(err.Error())
  	case <-p.complete:
  		log.Infof("(conn=%v, request=%s) successfully received error and data streams", h.sourceConn, p.requestID)
  	}
  	h.removeStreamPair(p.requestID)
  }
docs: // monitorStreamPair waits for the pair to receive both its error and data
  // streams, or for the timeout to expire (whichever happens first), and then
  // removes the pair.