t.Fatalf("want %d subscribers, got %d", want, got)
	}
}

func TestSubscribeExceedingLimit(t *testing.T) {
	ps := New[Maskable, Maskable](2)
	ch1 := make(chan Maskable, 1)
	ch2 := make(chan Maskable, 1)
	ch3 := make(chan Maskable, 1)
	doneCh := make(chan struct{})
	defer close(doneCh)
	if err := ps.Subscribe(MaskAll, ch1, doneCh, nil); err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	// Data inbound to the handler
	var handlerIn chan []byte
	if inboundCap > 0 {
		m.inbound = make(chan []byte, inboundCap)
		handlerIn = make(chan []byte, 1)
		go func(inbound chan []byte) {
			wg.Wait()
			defer xioutil.SafeClose(handlerIn)
			m.handleInbound(c, inbound, handlerIn)
		}(m.inbound)
	}
	// Fill outbound block.
	// Each token represents a message that can be sent to the client without blocking.

	}
	return key
}

// replayItems - Reads the items from the store and replays.
func replayItems[I any](store Store[I], doneCh <-chan struct{}, log logger, id string) <-chan Key {
	keyCh := make(chan Key)

	go func() {
		defer xioutil.SafeClose(keyCh)

		retryTicker := time.NewTicker(retryInterval)
		defer retryTicker.Stop()

		for {

)

// Reader - JSON record reader for S3Select.
type Reader struct {
	args    *json.ReaderArgs
	input   chan simdjson.Stream
	decoded chan simdjson.Object

	// err will only be returned after decoded has been closed.
	err          *error
	readCloser   io.ReadCloser
	onReaderExit func()

	exitReader chan struct{}
	readerWg   sync.WaitGroup
}

// Read - reads single record.

	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  bpool.Pool[[]byte]        // pool of []byte objects for input
	kvDstPool   bpool.Pool[[]jstream.KVS] // pool of []jstream.KVS used for output

	if m.GetRLock(ctx, "", "", time.Second) {
		clocked <- true
		<-cunlock
		m.RUnlock()
		cdone <- true
	}
}

// Borrowed from rwmutex_test.go
func doTestParallelReaders(numReaders, gomaxprocs int) {
	runtime.GOMAXPROCS(gomaxprocs)
	m := NewLRWMutex()

	clocked := make(chan bool)
	cunlock := make(chan bool)
	cdone := make(chan bool)

	}()

	cleanReqs := make(chan struct{})
	gotCall := make(chan struct{})
	defer close(cleanReqs)
	// 1: Block forever
	h1 := func(payload []byte) ([]byte, *RemoteErr) {
		gotCall <- struct{}{}
		<-cleanReqs
		return nil, nil
	}
	// 2: Also block, but with streaming.
	h2 := StreamHandler{
		Handle: func(ctx context.Context, payload []byte, request <-chan []byte, resp chan<- []byte) *RemoteErr {

			select {
			case sub.ch <- item:
			default:
			}
		}
	}
}

// Subscribe - Adds a subscriber to pubsub system
func (ps *PubSub[T, M]) Subscribe(mask M, subCh chan T, doneCh <-chan struct{}, filter func(entry T) bool) error {
	totalSubs := atomic.AddInt32(&ps.numSubscribers, 1)
	if ps.maxSubscribers > 0 && totalSubs > ps.maxSubscribers {
		atomic.AddInt32(&ps.numSubscribers, -1)

	nbuf      [chunk]byte     // next internal buffer
	fillReq   chan struct{}
	fillReady chan int64
	readerErr error // underlying reader error, if any
}

func newScanner(r io.Reader) *scanner {
	sr := &scanner{
		end:       maxInt,
		fillReq:   make(chan struct{}),
		fillReady: make(chan int64),
	}

	go func() {
		var rpos int64 // total bytes read into buffer

		defer func() {

	remoteHost := remote.HostName()

	// 1: Echo
	serverSent := make(chan struct{})
	serverCanceled := make(chan struct{})
	register := func(manager *Manager) {
		errFatal(manager.RegisterStreamingHandler(handlerTest, StreamHandler{
			Handle: func(ctx context.Context, payload []byte, _ <-chan []byte, resp chan<- []byte) *RemoteErr {
				// Send many responses.
				// Test that this doesn't block.