code: func WriteMessage(w io.Writer, s ws.State, op ws.OpCode, p []byte) error {
  	return writeFrame(w, s, op, true, p)
  }
docs: // WriteMessage is a helper function that writes message to the w. It
  // constructs single frame with given operation code and payload.
  // It uses given state to prepare side-dependtend things, like cipher
  // payload bytes from client to server. It will not mutate p bytes if
  // cipher must be made.
  //
  // If you want to write message in fragmented frames, use Writer instead.