code: func Send(w MsgWriter, msgcode uint64, data interface{}) error {
  	size, r, err := rlp.EncodeToReader(data)
  	if err != nil {
  		return err
  	}
  	return w.WriteMsg(Msg{Code: msgcode, Size: uint32(size), Payload: r})
  }
docs: // Send writes an RLP-encoded message with the given code.
  // data should encode as an RLP list.