message1: {
                    parallel.syncAt(1)
                    parallel.syncAt(2)
                },
                message3: { parallel.syncAt(3) })
        Dispatch<String> target2 = new DispatchStub(
                message2: {
                    parallel.syncAt(2)
                    parallel.syncAt(3)
                })

        when:
        parallel.run {

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)
}

// go work sync

package workcmd

import (
	"cmd/go/internal/base"
	"cmd/go/internal/gover"
	"cmd/go/internal/imports"
	"cmd/go/internal/modload"
	"cmd/go/internal/toolchain"
	"context"

	"golang.org/x/mod/module"
)

var cmdSync = &base.Command{
	UsageLine: "go work sync",
	Short:     "sync workspace build list to modules",
	Long: `Sync syncs the workspace's build list back to the

	return res
}

func (j *join[T]) Register(f func(o Event[T])) Syncer {
	return registerHandlerAsBatched[T](j, f)
}

func (j *join[T]) RegisterBatch(f func(o []Event[T], initialSync bool), runExistingState bool) Syncer {
	sync := multiSyncer{}
	for _, c := range j.collections {
		sync.syncers = append(sync.syncers, c.RegisterBatch(f, runExistingState))
	}
	return sync
}

// nolint: unused // (not true, its to implement an interface)

	return maps.Values(s.vals)
}

func (s *staticList[T]) Register(f func(o Event[T])) Syncer {
	return registerHandlerAsBatched(s, f)
}

func (s *staticList[T]) Synced() Syncer {
	return alwaysSynced{}
}

func (s *staticList[T]) RegisterBatch(f func(o []Event[T], initialSync bool), runExistingState bool) Syncer {
	if runExistingState {
		f(slices.Map(s.List(), func(e T) Event[T] {
			return Event[T]{

var _ internalCollection[controllers.Object] = &informer[controllers.Object]{}

func (i *informer[I]) _internalHandler() {}

func (i *informer[I]) Synced() Syncer {
	return channelSyncer{
		name:   i.collectionName,
		synced: i.synced,
	}
}

// nolint: unused // (not true, its to implement an interface)
func (i *informer[I]) dump() {
	i.log.Errorf(">>> BEGIN DUMP")
	for _, obj := range i.inf.List(metav1.NamespaceAll, klabels.Everything()) {

	// using krt), registering directly is expected.
	Register(f func(o Event[T])) Syncer

	// Synced returns a Syncer which can be used to determine if the collection has synced. Once its synced, all dependencies have
	// been processed, and all handlers have been called with the results.
	Synced() Syncer

	// RegisterBatch registers a handler that accepts multiple events at once. This can be useful as an optimization.

 * // filter will not be deleted.
 * task sync(type: Sync) {
 *     from 'source'
 *     into 'dest'
 *     preserve {
 *         include 'extraDir/**'
 *         include 'dir1/**'
 *         exclude 'dir1/extra.txt'
 *     }
 * }
 * </pre>
 */
@DisableCachingByDefault(because = "Not worth caching")
public abstract class Sync extends AbstractCopyTask {

	v := d.val.Load()
	if v == nil {
		return nil
	}
	return []T{*v}
}

func (d *static[T]) Register(f func(o Event[T])) Syncer {
	return registerHandlerAsBatched[T](d, f)
}

func (d *static[T]) RegisterBatch(f func(o []Event[T], initialSync bool), runExistingState bool) Syncer {
	d.eventHandlers.Insert(f)
	if runExistingState {
		v := d.val.Load()
		if v != nil {
			f([]Event[T]{{
				New:   v,

NAME       CLUSTER      CDS          LDS         EDS         RDS          ECDS         ISTIOD      VERSION
proxy1     cluster1     STALE        SYNCED      SYNCED      NOT SENT     SYNCED       istiod1     1.20
proxy2     cluster2     STALE        SYNCED      STALE       SYNCED       STALE        istiod2     1.19
proxy3     cluster3     NOT SENT     ERROR       STALE       NOT SENT     NOT SENT     istiod3     1.20