code: func (ev *msgEventer) ReadMsg() (Msg, error) {
  	msg, err := ev.MsgReadWriter.ReadMsg()
  	if err != nil {
  		return msg, err
  	}
  	ev.feed.Send(&PeerEvent{
  		Type:     PeerEventTypeMsgRecv,
  		Peer:     ev.peerID,
  		Protocol: ev.Protocol,
  		MsgCode:  &msg.Code,
  		MsgSize:  &msg.Size,
  	})
  	return msg, nil
  }
docs: // ReadMsg reads a message from the underlying MsgReadWriter and emits a
  // "message received" event