listeners = new ArrayList<Listener>();
  }

  @CanIgnoreReturnValue
  @Override
  public boolean cancel(boolean mayInterruptIfRunning) {
    if (!state.permitsPublicUserToTransitionTo(State.CANCELLED)) {
      return false;
    }

    this.mayInterruptIfRunning = mayInterruptIfRunning;
    state = State.CANCELLED;
    notifyAndClearListeners();

    if (delegate != null) {

function(e,t){"object"==typeof e&&(t=e,e=void 0),t=t||{};var c,f,p,n,d,r,h,g,i,o,v=ce.ajaxSetup({},t),y=v.context||v,m=v.context&&(y.nodeType||y.jquery)?ce(y):ce.event,x=ce.Deferred(),b=ce.Callbacks("once memory"),w=v.statusCode||{},a={},s={},u="canceled",T={readyState:0,getResponseHeader:function(e){var t;if(h){if(!n){n={};while(t=Wt.exec(p))n[t[1].toLowerCase()+" "]=(n[t[1].toLowerCase()+" "]||[]).concat(t[2])}t=n[e.toLowerCase()+" "]}return null==t?null:t.join(", ")},getAllResponseHeaders:function(){return...

      // before the cancelled future completes, it will synchronously complete both the newFuture
      // from the cancelled operation and its own. This can cause one runnable to queue two tasks,
      // breaking the invariant this method relies on to iteratively run the next task after the
      // previous one completes.
      if (get() == RunningState.CANCELLED) {
        delegate = null;
        sequencer = null;

      AbstractFutureBenchmarks.awaitWaiting(thread);
    }
    switch (state) {
      case NOT_DONE:
        break;
      case FINISHED:
        f.set(null);
        break;
      case CANCELLED:
        f.cancel(false);
        break;
      case FAILED:
        f.setException(new Exception());
        break;
    }
    return f;
  }

   * write.
   *
   * 2. visibility of the writes to an afterDone() call triggered by cancel():
   *
   * Since these fields are non-final that means that TimeoutFuture is not being 'safely published',
   * thus a motivated caller may be able to expose the reference to another thread that would then
   * call cancel() and be unable to cancel the delegate.

	ctx, cancel := context.WithCancel(ctx)

	target := &WebhookTarget{
		id:         event.TargetID{ID: id, Name: "webhook"},
		args:       args,
		loggerOnce: loggerOnce,
		transport:  transport,
		cancel:     cancel,
		cancelCh:   ctx.Done(),
	}

	return target, nil

/**
 * A {@link ListenableFuture} whose result can be set by a {@link #set(Object)}, {@link
 * #setException(Throwable)} or {@link #setFuture(ListenableFuture)} call. It can also, like any
 * other {@code Future}, be {@linkplain #cancel cancelled}.
 *
 * <p>{@code SettableFuture} is the recommended {@code ListenableFuture} implementation when your
 * task cannot be implemented with {@link ListeningExecutorService}, the various {@link Futures}

   * input future and that of the future returned by the chain function. That is, if the returned
   * {@code Future} is cancelled, it will attempt to cancel the other two, and if either of the
   * other two is cancelled, the returned {@code Future} will receive a callback in which it will
   * attempt to cancel itself.
   *
   * <p>This method is similar to {@link java.util.concurrent.CompletableFuture#thenCompose} and

/**
 * A {@link ListenableFuture} whose result can be set by a {@link #set(Object)}, {@link
 * #setException(Throwable)} or {@link #setFuture(ListenableFuture)} call. It can also, like any
 * other {@code Future}, be {@linkplain #cancel cancelled}.
 *
 * <p>{@code SettableFuture} is the recommended {@code ListenableFuture} implementation when your
 * task cannot be implemented with {@link ListeningExecutorService}, the various {@link Futures}

      @Override
      @SuppressWarnings("Interruption") // We are propagating an interrupt from a caller.
      public void cancel(boolean mayInterruptIfRunning) {
        /*
         * Lock to ensure that a task cannot be rescheduled while a cancel is ongoing.
         *
         * In theory, cancel() could execute arbitrary listeners -- bad to do while holding a lock.