// 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() {

The handler function has this signature.

Sample handler:
```go
    handler :=  func(ctx context.Context, payload []byte, in <-chan []byte, out chan<- []byte) *RemoteErr {
        fmt.Println("Got request with initial payload", p, "from", GetCaller(ctx context.Context))
        fmt.Println("Subroute:", GetSubroute(ctx))
        for {
            select {

func readMultipleFiles(ctx context.Context, disks []StorageAPI, req ReadMultipleReq, readQuorum int) ([]ReadMultipleResp, error) {
	resps := make([]chan ReadMultipleResp, len(disks))
	for i := range resps {
		resps[i] = make(chan ReadMultipleResp, len(req.Files))
	}
	g := errgroup.WithNErrs(len(disks))
	// Read files in parallel across disks.
	for index := range disks {
		index := index

	globalBucketObjectLockSys = &BucketObjectLockSys{}
	globalBucketVersioningSys = &BucketVersioningSys{}
	es := newExpiryState(context.Background(), objAPI, 0)
	workers := []chan expiryOp{make(chan expiryOp)}
	es.workers.Store(&workers)
	globalExpiryState = es
	var wg sync.WaitGroup
	wg.Add(1)
	expired := make([]ObjectToDelete, 0, 5)
	go func() {
		defer wg.Done()

	return d.disk.GetDiskID()
}

func (d *naughtyDisk) SetDiskID(id string) {
	d.disk.SetDiskID(id)
}

func (d *naughtyDisk) NSScanner(ctx context.Context, cache dataUsageCache, updates chan<- dataUsageEntry, scanMode madmin.HealScanMode, weSleep func() bool) (info dataUsageCache, err error) {
	if err := d.calcError(); err != nil {
		return info, err
	}

	setIndex, poolIndex int
	queued              time.Time
	scanMode            madmin.HealScanMode
}

// mrfState sncapsulates all the information
// related to the global background MRF.
type mrfState struct {
	opCh chan partialOperation
}

// Add a partial S3 operation (put/delete) when one or more disks are offline.
func (m *mrfState) addPartialOp(op partialOperation) {
	if m == nil {
		return
	}

	select {

	input        chan *queueItem  // input for workers
	queue        chan *queueItem  // output from workers in order
	err          error            // global error state, only touched by Reader.Read
	bufferPool   sync.Pool        // pool of []byte objects for input
	csvDstPool   sync.Pool        // pool of [][]string used for output

	case formatLZ4:
		r = lz4.NewReader(bf)
	case formatUnknown:
		r = bf
	default:
		return fmt.Errorf("Unsupported format %s", f)
	}
	tarReader := tar.NewReader(r)
	n := 0
	asyncWriters := make(chan struct{}, 16)
	var wg sync.WaitGroup

	var asyncErr error
	var asyncErrMu sync.Mutex
	for {
		if !o.ignoreErrs {
			asyncErrMu.Lock()
			err := asyncErr
			asyncErrMu.Unlock()
			if err != nil {

		// 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()

	id         event.TargetID
	args       WebhookArgs
	transport  *http.Transport
	httpClient *http.Client
	store      store.Store[event.Event]
	loggerOnce logger.LogOnce
	cancel     context.CancelFunc
	cancelCh   <-chan struct{}

	addr string // full address ip/dns with a port number, e.g.  x.x.x.x:8080
}

// ID - returns target ID.
func (target *WebhookTarget) ID() event.TargetID {
	return target.id
}