return false
	}
	defer ec.queue.Done(key)

	err := ec.syncFn(key)
	if err == nil {
		ec.queue.Forget(key)
		return true
	}

	utilruntime.HandleError(fmt.Errorf("%v failed with: %v", key, err))
	ec.queue.AddRateLimited(key)

	return true
}

// sync is used to turn CRDs into the Established state.
func (ec *EstablishingController) sync(key string) error {
	cachedCRD, err := ec.crdLister.Get(key)

	// To allow injection for testing.
	syncFn func(key string) error

	queue workqueue.TypedRateLimitingInterface[string]

	// last protectedAnnotation value this controller updated the condition per CRD name (to avoid two
	// different version of the apiextensions-apiservers in HA to fight for the right message)
	lastSeenProtectedAnnotationLock sync.Mutex
	lastSeenProtectedAnnotation     map[string]string
}

	crdSynced cache.InformerSynced

	// To allow injection for testing.
	syncFn func(key string) error

	queue workqueue.TypedRateLimitingInterface[string]

	// last generation this controller updated the condition per CRD name (to avoid two
	// different version of the apiextensions-apiservers in HA to fight for the right message)
	lastSeenGenerationLock sync.Mutex
	lastSeenGeneration     map[string]int64
}

	crdLister  listers.CustomResourceDefinitionLister
	crdsSynced cache.InformerSynced

	// To allow injection for testing.
	syncFn func(string) error

	queue workqueue.TypedRateLimitingInterface[string]

	openAPIV3Service *handler3.OpenAPIService

	// specs per version and per CRD name
	lock             sync.Mutex
	specsByGVandName map[schema.GroupVersion]map[string]*spec3.OpenAPI
}

	crdsSynced cache.InformerSynced

	// To allow injection for testing.
	syncFn func(string) error

	queue workqueue.TypedRateLimitingInterface[string]

	staticSpec *spec.Swagger

	openAPIService *handler.OpenAPIService

	// specs by name. The specs are lazily constructed on request.
	// The lock is for the map only.
	lock        sync.Mutex
	specsByName map[string]*specCache
}

		AddFunc:    c.addCustomResourceDefinition,
		UpdateFunc: c.updateCustomResourceDefinition,
		DeleteFunc: c.deleteCustomResourceDefinition,
	})

	c.syncFn = c.sync

	return c
}

func (c *DiscoveryController) sync(version schema.GroupVersion) error {

	apiVersionsForDiscovery := []metav1.GroupVersionForDiscovery{}
	apiResourcesForDiscovery := []metav1.APIResource{}

	crdInformer.Informer().AddEventHandler(cache.ResourceEventHandlerFuncs{
		AddFunc:    c.addCustomResourceDefinition,
		UpdateFunc: c.updateCustomResourceDefinition,
	})

	c.syncFn = c.sync

	return c
}

func (c *CRDFinalizer) sync(key string) error {
	cachedCRD, err := c.crdLister.Get(key)
	if apierrors.IsNotFound(err) {
		return nil
	}
	if err != nil {
		return err
	}

	// no work to do

		AddFunc:    c.addCustomResourceDefinition,
		UpdateFunc: c.updateCustomResourceDefinition,
		DeleteFunc: c.deleteCustomResourceDefinition,
	})

	c.syncFn = c.sync

	return c
}

func (c *NamingConditionController) getAcceptedNamesForGroup(group string) (allResources sets.String, allKinds sets.String) {
	allResources = sets.String{}
	allKinds = sets.String{}

import "istio.io/istio/pkg/kube"

type Syncer interface {
	WaitUntilSynced(stop <-chan struct{}) bool
	HasSynced() bool
}

var (
	_ Syncer = channelSyncer{}
	_ Syncer = pollSyncer{}
)

type channelSyncer struct {
	name   string
	synced <-chan struct{}
}

func (c channelSyncer) WaitUntilSynced(stop <-chan struct{}) bool {
	return waitForCacheSync(c.name, stop, c.synced)
}

//
// This method is safe to call from multiple goroutines.
func (sync *NodeSync) Update(node *v1.Node) {
	sync.opChan <- &updateOp{node}
}

// Delete performs the sync operations necessary to remove the node from the
// IPAM state.
//
// This method is safe to call from multiple goroutines.
func (sync *NodeSync) Delete(node *v1.Node) {
	sync.opChan <- &deleteOp{node}
	close(sync.opChan)
}