import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.base.MoreObjects;

/**
 * Wraps an event that was posted, but which had no subscribers and thus could not be delivered.
 *
 * <p>Registering a DeadEvent subscriber is useful for debugging or logging, as it can detect
 * misconfigurations in a system's event distribution.
 *
 * @author Cliff Biffle
 * @since 10.0
 */

   *     down the executor after the last event has been posted to this event bus.
   * @param subscriberExceptionHandler Handler used to handle exceptions thrown from subscribers.
   *     See {@link SubscriberExceptionHandler} for more information.
   * @since 16.0
   */
  public AsyncEventBus(Executor executor, SubscriberExceptionHandler subscriberExceptionHandler) {

// for this node or peers
func (sys *HTTPConsoleLoggerSys) HasLogListeners() bool {
	return sys != nil && sys.pubsub.Subscribers() > 0
}

// Subscribe starts console logging for this node.
func (sys *HTTPConsoleLoggerSys) Subscribe(subCh chan log.Info, doneCh <-chan struct{}, node string, last int, logKind madmin.LogMask, filter func(entry log.Info) bool) error {
	// Enable console logging for remote client.

		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

	// Listen Publisher uses nonblocking publish and hence does not wait for slow subscribers.
	// Use buffered channel to take care of burst sends or slow w.Write()
	ch := make(chan event.Event, globalAPIConfig.getRequestsPoolCapacity())
	err := globalHTTPListen.Subscribe(mask, ch, ctx.Done(), func(ev event.Event) bool {
		if ev.S3.Bucket.Name != "" && values.Get(peerRESTListenBucket) != "" {

 * the {@link EventBus}.
 *
 * <p>Unless also annotated with @{@link AllowConcurrentEvents}, event subscriber methods will be
 * invoked serially by each event bus that they are registered with.
 *
 * @author Cliff Biffle
 * @since 10.0
 */
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
@Keep

 * the {@link EventBus}.
 *
 * <p>Unless also annotated with @{@link AllowConcurrentEvents}, event subscriber methods will be
 * invoked serially by each event bus that they are registered with.
 *
 * @author Cliff Biffle
 * @since 10.0
 */
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
@Keep

   * @param subscriber The source subscriber context.
   * @param subscriberMethod the subscribed method.
   */
  SubscriberExceptionContext(
      EventBus eventBus, Object event, Object subscriber, Method subscriberMethod) {
    this.eventBus = checkNotNull(eventBus);
    this.event = checkNotNull(event);
    this.subscriber = checkNotNull(subscriber);

import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * Marks an event subscriber method as being thread-safe. This annotation indicates that EventBus
 * may invoke the event subscriber simultaneously from multiple threads.
 *
 * <p>This does not mark the method, and so should be used in combination with {@link Subscribe}.
 *
 * @author Cliff Biffle
 * @since 10.0
 */
@Retention(RetentionPolicy.RUNTIME)

    Iterator<Subscriber> two = registry.getSubscribers("");
    assertEquals(s1, two.next().target);
    assertEquals(o1, two.next().target);
    assertFalse(two.hasNext());
  }

  public static class StringSubscriber {

    @Subscribe
    public void handle(String s) {}
  }

  public static class IntegerSubscriber {

    @Subscribe
    public void handle(Integer i) {}
  }