code: func (h *Handler) ValidateMessageType(msgType message.Type) (exitOnError bool, err error) {
  	if h.MessageType != msgType {
  		switch msgType {
  		case message.Request:
  			err = constants.ErrRequestOnNotify
  			exitOnError = true
  
  		case message.Notify:
  			err = constants.ErrNotifyOnRequest
  		}
  	}
  	return
  }
docs: // ValidateMessageType validates a given message type against the handler's one
  // and returns an error if it is a mismatch and a boolean indicating if the caller should
  // exit in the presence of this error or not.