code: func (f *dynamicSharedInformerFactory) WaitForCacheSync(stopCh <-chan struct{}) map[schema.GroupVersionResource]bool {
  	informers := func() map[schema.GroupVersionResource]cache.SharedIndexInformer {
  		f.lock.Lock()
  		defer f.lock.Unlock()
  
  		informers := map[schema.GroupVersionResource]cache.SharedIndexInformer{}
  		for informerType, informer := range f.informers {
  			if f.startedInformers[informerType] {
  				informers[informerType] = informer.Informer()
  			}
  		}
  		return informers
  	}()
  
  	res := map[schema.GroupVersionResource]bool{}
  	for informType, informer := range informers {
  		res[informType] = cache.WaitForCacheSync(stopCh, informer.HasSynced)
  	}
  	return res
  }
docs: // WaitForCacheSync waits for all started informers' cache were synced.