private final Iterator<Subscriber> subscribers;

      private Event(Object event, Iterator<Subscriber> subscribers) {
        this.event = event;
        this.subscribers = subscribers;
      }
    }
  }

  /** Implementation of a {@link #legacyAsync()} dispatcher. */
  private static final class LegacyAsyncDispatcher extends Dispatcher {

		return 0
	}
	return atomic.LoadInt32(&ps.numSubscribers)
}

// Subscribers returns the number of current subscribers for all types.
func (ps *PubSub[T, M]) Subscribers() int32 {
	return atomic.LoadInt32(&ps.numSubscribers)
}

// New inits a PubSub system with a limit of maximum
// subscribers unless zero is specified
func New[T Maskable, M Maskable](maxSubscribers int32) *PubSub[T, M] {

    }
  }

  @VisibleForTesting
  Set<Subscriber> getSubscribersForTesting(Class<?> eventType) {
    return MoreObjects.firstNonNull(subscribers.get(eventType), ImmutableSet.<Subscriber>of());
  }

  /**
   * Gets an iterator representing an immutable snapshot of all subscribers to the given event at
   * the time this method is called.
   */
  Iterator<Subscriber> getSubscribers(Object event) {

            i1,
            i2,
            i3, // Integer subscribers are dispatched to first.
            s1,
            s2, // Though each integer subscriber dispatches to all string subscribers,
            s1,
            s2, // those string subscribers aren't actually dispatched to until all integer
            s1,
            s2 // subscribers have finished.
            )
        .inOrder();
  }

	}
	ps.Lock()
	defer ps.Unlock()

	if len(ps.subs) != 2 {
		t.Fatalf("expected 2 subscribers")
	}
	if want, got := int32(2), ps.NumSubscribers(Mask(1)); got != want {
		t.Fatalf("want %d subscribers, got %d", want, got)
	}
	if want, got := int32(2), ps.NumSubscribers(Mask(2)); got != want {
		t.Fatalf("want %d subscribers, got %d", want, got)
	}
	if want, got := int32(2), ps.NumSubscribers(Mask(1|2)); got != want {

            i1,
            i2,
            i3, // Integer subscribers are dispatched to first.
            s1,
            s2, // Though each integer subscriber dispatches to all string subscribers,
            s1,
            s2, // those string subscribers aren't actually dispatched to until all integer
            s1,
            s2 // subscribers have finished.
            )
        .inOrder();
  }

  private @Nullable H subscriber;

  H getSubscriber() {
    return subscriber;
  }

  @Override
  protected void setUp() throws Exception {
    subscriber = createSubscriber();
    EventBus bus = new EventBus();
    bus.register(subscriber);
    bus.post(EVENT);
  }

  @Override
  protected void tearDown() throws Exception {
    subscriber = null;
  }

}

func activeListeners() int {
	// Bucket notification and http trace are not costly, it is okay to ignore them
	// while counting the number of concurrent connections
	return int(globalHTTPListen.Subscribers()) + int(globalTrace.Subscribers())
}

func waitForLowIO(maxIO int, maxWait time.Duration, currentIO func() int) {
	// No need to wait run at full speed.
	if maxIO <= 0 {
		return
	}

  private @Nullable H subscriber;

  H getSubscriber() {
    return subscriber;
  }

  @Override
  protected void setUp() throws Exception {
    subscriber = createSubscriber();
    EventBus bus = new EventBus();
    bus.register(subscriber);
    bus.post(EVENT);
  }

  @Override
  protected void tearDown() throws Exception {
    subscriber = null;
  }

		reqStartTime := time.Now().UTC()
		h.ServeHTTP(respRecorder, r)
		reqEndTime := time.Now().UTC()

		if globalTrace.NumSubscribers(madmin.TraceS3|madmin.TraceInternal) == 0 {
			// no subscribers nothing to trace.
			return
		}

		tt := madmin.TraceInternal
		if strings.HasPrefix(tc.FuncName, "s3.") {
			tt = madmin.TraceS3
		}

		// Calculate input body size with headers