code: func WriteMessageN(w io.Writer, msg Message, pver uint32, btcnet BitcoinNet) (int, error) {
  	return WriteMessageWithEncodingN(w, msg, pver, btcnet, BaseEncoding)
  }
docs: // WriteMessageN writes a bitcoin Message to w including the necessary header
  // information and returns the number of bytes written.    This function is the
  // same as WriteMessage except it also returns the number of bytes written.