code: func NewSPDYExecutorForTransports(transport http.RoundTripper, upgrader spdy.Upgrader, method string, url *url.URL) (Executor, error) {
  	return NewSPDYExecutorForProtocols(
  		transport, upgrader, method, url,
  		remotecommand.StreamProtocolV4Name,
  		remotecommand.StreamProtocolV3Name,
  		remotecommand.StreamProtocolV2Name,
  		remotecommand.StreamProtocolV1Name,
  	)
  }
docs: // NewSPDYExecutorForTransports connects to the provided server using the given transport,
  // upgrades the response using the given upgrader to multiplexed bidirectional streams.