code: func NewDialer(upgrader Upgrader, client *http.Client, method string, url *url.URL) httpstream.Dialer {
  	return &dialer{
  		client:   client,
  		upgrader: upgrader,
  		method:   method,
  		url:      url,
  	}
  }
docs: // NewDialer will create a dialer that connects to the provided URL and upgrades the connection to SPDY.