if !h.valid() {
		return nil, ErrUnknownHandler
	}
	if c.State() != StateConnected {
		return nil, ErrDisconnected
	}
	handler := c.handlers.subStreams[makeZeroSubHandlerID(h)]
	if handler == nil {
		if debugPrint {
			fmt.Println("want", makeZeroSubHandlerID(h), c.route, "got", c.handlers.subStreams)
		}
		return nil, ErrUnknownHandler
	}

	var requests chan []byte
	var responses chan Response