code: func (adapter *Adapter) Watch(resyncName string, changeChan chan datasync.ChangeEvent,
  	resyncChan chan datasync.ResyncEvent, keyPrefixes ...string) (datasync.WatchRegistration, error) {
  
  	if adapter.Watcher != nil {
  		return adapter.Watcher.Watch(resyncName, changeChan, resyncChan, keyPrefixes...)
  	}
  	logrus.DefaultLogger().Debug("KeyValProtoWatcher is nil")
  
  	return nil, nil
  }
docs: // Watch uses Kafka KeyValProtoWatcher Topic KeyValProtoWatcher.