code: func (srv *Server) Send() (err error) {
  	replyMsg := srv.responseMsg
  	if srv.isSafeMode {
  		//安全模式下对消息进行加密
  		var encryptedMsg []byte
  		encryptedMsg, err = util.EncryptMsg(srv.random, srv.responseRawXMLMsg, srv.AppID, srv.EncodingAESKey)
  		if err != nil {
  			return
  		}
  		//TODO 如果获取不到timestamp nonce 则自己生成
  		timestamp := srv.timestamp
  		timestampStr := strconv.FormatInt(timestamp, 10)
  		msgSignature := util.Signature(srv.Token, timestampStr, srv.nonce, string(encryptedMsg))
  		replyMsg = message.ResponseEncryptedXMLMsg{
  			EncryptedMsg: string(encryptedMsg),
  			MsgSignature: msgSignature,
  			Timestamp:    timestamp,
  			Nonce:        srv.nonce,
  		}
  	}
  	if replyMsg != nil {
  		srv.XML(replyMsg)
  	}
  	return
  }
docs: //Send 将自定义的消息发送