Future<?> possiblyIgnoredError = threadPool.submit(new Producer(q, 20));
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
      Future<?> possiblyIgnoredError1 = threadPool.submit(new Producer(q, 20));
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
      Future<?> possiblyIgnoredError2 = threadPool.submit(new Producer(q, 20));

  @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

            },
            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() {

      Future<?> possiblyIgnoredError = threadPool.submit(new Producer(q, 20));
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
      Future<?> possiblyIgnoredError1 = threadPool.submit(new Producer(q, 20));
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
      Future<?> possiblyIgnoredError2 = threadPool.submit(new Producer(q, 20));

              } catch (Exception e) {
                throw new RuntimeException(e);
              }
            }
          };
      executor.execute(errorTask);
      service.execute(barrierTask); // submit directly to the service
      // the barrier task runs after the error task so we know that the error has been observed by
      // SequentialExecutor by the time the barrier is satisfied
      barrier.await(1, TimeUnit.SECONDS);

      final String s = "a" + i;
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
      Future<?> possiblyIgnoredError =
          threadPool.submit(
              new Runnable() {
                @Override
                public void run() {
                  cache.getUnchecked(s);
                  computedCount.incrementAndGet();

 * 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

    Thread otherThread =
        new Thread(
            new Runnable() {
              @Override
              public void run() {
                try {
                  Future<?> future = executor.submit(incrementTask);
                  assertTrue(future.isDone());
                  assertEquals(1, threadLocalCount.get().intValue());
                } catch (Throwable t) {
                  throwableFromOtherThread.set(t);

    Thread otherThread =
        new Thread(
            new Runnable() {
              @Override
              public void run() {
                try {
                  Future<?> future = executor.submit(incrementTask);
                  assertTrue(future.isDone());
                  assertEquals(1, threadLocalCount.get().intValue());
                } catch (Throwable t) {
                  throwableFromOtherThread.set(t);