// Use buffered channel to take care of burst sends or slow w.Write()
	mergeCh := make(chan []byte, globalAPIConfig.getRequestsPoolCapacity()*len(globalEndpoints.Hostnames()))
	localCh := make(chan event.Event, globalAPIConfig.getRequestsPoolCapacity())

	// Convert local messages to JSON and send to mergeCh
	go func() {

		confirms := ch.NotifyPublish(make(chan amqp091.Confirmation, 1))
		if err := ch.Confirm(false); err != nil {
			ch.Close()
			return nil, nil, err
		}
		return ch, confirms, nil
	}

	return ch, nil, nil
}

// send - sends an event to the AMQP091.
func (target *AMQPTarget) send(eventData event.Event, ch *amqp091.Channel, confirms chan amqp091.Confirmation) error {

	// All responses *must* be read by the caller until either an error is returned or the channel is closed.
	// Canceling the context will cause the context cancellation error to be returned.
	responses <-chan Response
	cancel    context.CancelCauseFunc

	// Requests sent to the server.
	// If the handler is defined with 0 incoming capacity this will be nil.
	// Channel *must* be closed to signal the end of the stream.

		// not be required but makes reproduction much easier.
		nsLk.lockMapMutex.Lock()

		// lk3 blocks.
		lk3ch := make(chan bool)
		go func() {
			lk3ch <- nsLk.lock(ctx, "volume", "path", "source", "opsID", false, 0)
		}()

		// lk4, blocks.
		lk4ch := make(chan bool)
		go func() {
			lk4ch <- nsLk.lock(ctx, "volume", "path", "source", "opsID", false, 0)
		}()
		runtime.Gosched()

type httpListener struct {
	opts        TCPOptions
	listeners   []net.Listener    // underlying TCP listeners.
	acceptCh    chan acceptResult // channel where all TCP listeners write accepted connection.
	ctxDoneCh   <-chan struct{}
	ctxCanceler context.CancelFunc
}

// start - starts separate goroutine for each TCP listener.  A valid new connection is passed to httpListener.acceptCh.

// Singleton contains a pointer to T that must be set once.
// Until the value is set all Get() calls will block.
type Singleton[T any] struct {
	v   *T
	set chan struct{}
}

// NewSingleton creates a new unset singleton.
func NewSingleton[T any]() *Singleton[T] {
	return &Singleton[T]{set: make(chan struct{}), v: nil}
}

// Get will return the singleton value.
func (s *Singleton[T]) Get() *T {
	<-s.set
	return s.v
}

			wantExpired: nil,
		},
	}
	for i, test := range tests {
		t.Run(fmt.Sprintf("TestApplyNewerNoncurrentVersionsLimit-%d", i), func(t *testing.T) {
			workers := []chan expiryOp{make(chan expiryOp)}
			es.workers.Store(&workers)
			workerReady := make(chan struct{})
			var wg sync.WaitGroup
			wg.Add(1)
			var gotExpired []ObjectToDelete
			go expiryWorker(&wg, workerReady, workers[0], &gotExpired)
			<-workerReady

			}
			consolidatedReport.BucketStats[opts] = d
		}
	}
	return consolidatedReport
}

func (sys *NotificationSys) collectPeerMetrics(ctx context.Context, peerChannels []<-chan MetricV2, g *errgroup.Group) <-chan MetricV2 {
	ch := make(chan MetricV2)
	var wg sync.WaitGroup
	for index, err := range g.Wait() {
		if err != nil {
			if sys.peerClients[index] != nil {

	saver := z.serverPools[o.pool].sets[o.set]

	// Disconnect from call above, but cancel on exit.
	listCtx, cancel := context.WithCancel(GlobalContext)
	saveCh := make(chan metaCacheEntry, metacacheBlockSize)
	inCh := make(chan metaCacheEntry, metacacheBlockSize)
	outCh := make(chan metaCacheEntry, o.Limit)

	filteredResults := o.gatherResults(ctx, outCh)

	mc := o.newMetacache()

}

// Borrowed from mutex_test.go
func HammerMutex(m *DRWMutex, loops int, cdone chan bool) {
	for range loops {
		m.Lock(id, source)
		m.Unlock(context.Background())
	}
	cdone <- true
}

// Borrowed from mutex_test.go
func TestMutex(t *testing.T) {
	loops := 200
	if testing.Short() {
		loops = 5
	}
	c := make(chan bool)
	m := NewDRWMutex(ds, "test")
	for range 10 {
		go HammerMutex(m, loops, c)