code: func (s *ServiceController) enqueueService(obj interface{}) {
  	key, err := controller.KeyFunc(obj)
  	if err != nil {
  		klog.Errorf("Couldn't get key for object %#v: %v", obj, err)
  		return
  	}
  	s.queue.Add(key)
  }
docs: // obj could be an *v1.Service, or a DeletionFinalStateUnknown marker item.