given:
        manager.addListener(fooListener1)
        manager.addListener(fooListener2)

        // get the broadcaster and then add more listeners (because broadcasters
        // are cached and so must be maintained correctly after getting defined
        def broadcaster = manager.getBroadcaster(TestFooListener.class)

        manager.addListener(fooListener3)

        when:

    future.addListener(before, directExecutor());
    future.addListener(bad, directExecutor());
    future.addListener(after, directExecutor());

    future.set(1); // BadRunnableException must not propagate.

    before.assertRun();
    after.assertRun();
  }

  public void testNullListener() {
    try {
      future.addListener(null, directExecutor());
      fail();

    future.addListener(before, directExecutor());
    future.addListener(bad, directExecutor());
    future.addListener(after, directExecutor());

    future.set(1); // BadRunnableException must not propagate.

    before.assertRun();
    after.assertRun();
  }

  public void testNullListener() {
    try {
      future.addListener(null, directExecutor());
      fail();

        listener3.getPath() >> b.path

        when:
        graph.add(a)
        graph.addListener(listener1)
        graph.add(b)

        then:
        1 * listener1.onDiscovered(graph.root)
        1 * listener1.onDiscovered(a) >> { graph.addListener(listener2); false }
        1 * listener1.onDiscovered(b) >> { graph.addListener(listener3); false }
        1 * listener2.onDiscovered(b)
        1 * listener3.onDiscovered(b)

                    println 'gradle.addListener(ComboListener) from $source'
                }
                void settingsEvaluated(Settings settings) {
                    println 'gradle.addListener(ComboListener) from $source'
                }
                void projectsLoaded(Gradle gradle) {
                    println 'gradle.addListener(ComboListener) from $source'
                }

        when:
        runner.execute(buildAction, buildSessionContext)

        then:
        1 * listenerManager.addListener(listener1)
        1 * listenerManager.addListener(listener2)
        1 * buildOperationListenerManager.addListener(listener1)
        1 * buildOperationListenerManager.addListener(listener2)

        then:
        1 * delegate.execute(buildAction, buildSessionContext)

        then:

    listenable.addListener(earlyListener, directExecutor());

    input.allowGetToComplete.countDown();
    // Now give the get() thread time to finish:
    assertTrue(earlyListener.wasRun.await(1, SECONDS));

    // Now test an additional addListener call, which will be run in-thread:
    RecordingRunnable lateListener = new RecordingRunnable();
    listenable.addListener(lateListener, directExecutor());

        TaskExecutionListener | "taskExecutionListener" | "gradle.addListener"                        | "Gradle.addListener"
        TaskExecutionListener | "taskExecutionListener" | "gradle.taskGraph.addTaskExecutionListener" | "TaskExecutionGraph.addTaskExecutionListener"
        TaskActionListener    | "taskActionListener"    | "gradle.addListener"                        | "Gradle.addListener"
    }

    ListenerCallQueue<Object> queue = new ListenerCallQueue<>();
    queue.addListener(listener1, directExecutor());

    Multiset<Object> counters = ConcurrentHashMultiset.create();
    queue.enqueue(incrementingEvent(counters, listener1, 1));
    queue.enqueue(incrementingEvent(counters, listener1, 2));

    Object listener2 = new Object();
    queue.addListener(listener2, directExecutor());

    ListenerCallQueue<Object> queue = new ListenerCallQueue<>();
    queue.addListener(listener1, directExecutor());

    Multiset<Object> counters = ConcurrentHashMultiset.create();
    queue.enqueue(incrementingEvent(counters, listener1, 1));
    queue.enqueue(incrementingEvent(counters, listener1, 2));

    Object listener2 = new Object();
    queue.addListener(listener2, directExecutor());