@GwtIncompatible
  public static Executor newSequentialExecutor(Executor delegate) {
    return new SequentialExecutor(delegate);
  }

  /**
   * Creates an {@link ExecutorService} whose {@code submit} and {@code invokeAll} methods submit
   * {@link ListenableFutureTask} instances to the given delegate executor. Those methods, as well
   * as {@code execute} and {@code invokeAny}, are implemented in terms of calls to {@code

 * Tasks execute with the same happens-before order that the function calls to {@link #submit} and
 * {@link #submitAsync} that submitted those tasks had.
 *
 * <p>This class has limited support for cancellation and other "early completions":
 *
 * <ul>
 *   <li>While calls to {@code submit} and {@code submitAsync} return a {@code Future} that can be

    List<Future<?>> futures = Lists.newArrayList();
    ExecutorService executor = Executors.newFixedThreadPool(10);
    int numberOfCatchers = 10000;
    for (int i = 0; i < numberOfCatchers; i++) {
      futures.add(executor.submit(new Registrator(bus, catchers)));
    }
    for (int i = 0; i < numberOfCatchers; i++) {
      futures.get(i).get();
    }
    assertEquals("Unexpected number of catchers in the list", numberOfCatchers, catchers.size());

    List<Future<?>> futures = Lists.newArrayList();
    ExecutorService executor = Executors.newFixedThreadPool(10);
    int numberOfCatchers = 10000;
    for (int i = 0; i < numberOfCatchers; i++) {
      futures.add(executor.submit(new Registrator(bus, catchers)));
    }
    for (int i = 0; i < numberOfCatchers; i++) {
      futures.get(i).get();
    }
    assertEquals("Unexpected number of catchers in the list", numberOfCatchers, catchers.size());

    final CyclicBarrier barrier = new CyclicBarrier(threadCount);
    ImmutableList.Builder<Future<?>> futures = ImmutableList.builder();
    for (int i = 0; i < threadCount; i++) {
      futures.add(
          executor.submit(
              new Callable<@Nullable Void>() {
                @Override
                public @Nullable Void call() throws Exception {
                  barrier.await();

      currentFuture.set(future);
      for (Callable<?> task : allTasks) {
        @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
        Future<?> possiblyIgnoredError = executor.submit(task);
      }
      awaitUnchecked(barrier);
      assertThat(future.isDone()).isTrue();
      // inspect state and ensure it is correct!
      // asserts that all get calling threads received the same value

            },
            directExecutor());
    for (int i = 0; i < 25_000; i++) {
      serializer.submit(Callables.<Void>returning(null), directExecutor()).cancel(true);
      unused = serializer.submit(Callables.<Void>returning(null), directExecutor());
    }
    ListenableFuture<Integer> stackDepthCheck =
        serializer.submit(
            new Callable<Integer>() {
              @Override
              public Integer call() {

            },
            directExecutor());
    for (int i = 0; i < 25_000; i++) {
      serializer.submit(Callables.<Void>returning(null), directExecutor()).cancel(true);
      unused = serializer.submit(Callables.<Void>returning(null), directExecutor());
    }
    ListenableFuture<Integer> stackDepthCheck =
        serializer.submit(
            new Callable<Integer>() {
              @Override
              public Integer call() {

      final Path file, final Path target, ExecutorService executor) {
    @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
    Future<?> possiblyIgnoredError =
        executor.submit(
            new Runnable() {
              @Override
              public void run() {
                boolean createSymlink = false;
                while (!Thread.interrupted()) {
                  try {

      currentFuture.set(future);
      for (Callable<?> task : allTasks) {
        @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
        Future<?> possiblyIgnoredError = executor.submit(task);
      }
      awaitUnchecked(barrier);
      assertThat(future.isDone()).isTrue();
      // inspect state and ensure it is correct!
      // asserts that all get calling threads received the same value