code: func (cn *connection) Post(msg pp.Message) {
  	torrent.Add(fmt.Sprintf("messages posted of type %s", msg.Type.String()), 1)
  	// We don't need to track bytes here because a connection.w Writer wrapper
  	// takes care of that (although there's some delay between us recording
  	// the message, and the connection writer flushing it out.).
  	cn.writeBuffer.Write(msg.MustMarshalBinary())
  	// Last I checked only Piece messages affect stats, and we don't post
  	// those.
  	cn.wroteMsg(&msg)
  	cn.tickleWriter()
  }
docs: // Writes a message into the write buffer.