List<Future<String>> results;

    results = service.invokeAll(callables);
    assertThat(getOnlyElement(results)).isInstanceOf(TrustedListenableFutureTask.class);

    results = service.invokeAll(callables, 1, SECONDS);
    assertThat(getOnlyElement(results)).isInstanceOf(TrustedListenableFutureTask.class);

    /*
     * TODO(cpovirk): move ForwardingTestCase somewhere common, and use it to
     * test the forwarded methods

    ListenableFuture<@Nullable Void> oldFuture = ref.getAndSet(newFuture);

    // Invoke our task once the previous future completes.
    TrustedListenableFutureTask<T> taskFuture = TrustedListenableFutureTask.create(task);
    oldFuture.addListener(taskFuture, taskExecutor);

    ListenableFuture<T> outputFuture = Futures.nonCancellationPropagating(taskFuture);

      ClosingCallable<V> callable, Executor executor) {
    checkNotNull(callable);
    CloseableList closeables = new CloseableList();
    TrustedListenableFutureTask<V> task =
        TrustedListenableFutureTask.create(
            new Callable<V>() {
              @Override
              @ParametricNullness
              public V call() throws Exception {