code: func (ctrl *PersistentVolumeController) resync() {
  	klog.V(4).Infof("resyncing PV controller")
  
  	pvcs, err := ctrl.claimLister.List(labels.NewSelector())
  	if err != nil {
  		klog.Warningf("cannot list claims: %s", err)
  		return
  	}
  	for _, pvc := range pvcs {
  		ctrl.enqueueWork(ctrl.claimQueue, pvc)
  	}
  
  	pvs, err := ctrl.volumeLister.List(labels.NewSelector())
  	if err != nil {
  		klog.Warningf("cannot list persistent volumes: %s", err)
  		return
  	}
  	for _, pv := range pvs {
  		ctrl.enqueueWork(ctrl.volumeQueue, pv)
  	}
  }
docs: // resync supplements short resync period of shared informers - we don't want
  // all consumers of PV/PVC shared informer to have a short resync period,
  // therefore we do our own.