code: func WriteMessage(w io.Writer, msg Message, pver uint32, btcnet BitcoinNet) error {
  	_, err := WriteMessageN(w, msg, pver, btcnet)
  	return err
  }
docs: // WriteMessage writes a bitcoin Message to w including the necessary header
  // information.  This function is the same as WriteMessageN except it doesn't
  // doesn't return the number of bytes written.  This function is mainly provided
  // for backwards compatibility with the original API, but it's also useful for
  // callers that don't care about byte counts.