AtomicInteger collisions = new AtomicInteger(0);

        // When generating nonces concurrently
        ExecutorService executor = Executors.newFixedThreadPool(threadCount);
        for (int t = 0; t < threadCount; t++) {
            executor.submit(() -> {
                try {
                    for (int i = 0; i < noncesPerThread; i++) {
                        byte[] nonce = context.generateNonce();

        int sessionCount = 10;
        ExecutorService executor = Executors.newFixedThreadPool(5);
        CountDownLatch latch = new CountDownLatch(sessionCount);

        for (int i = 0; i < sessionCount; i++) {
            final int sessionIndex = i;
            executor.submit(() -> {
                try {
                    String sessionId = "concurrent-session-" + sessionIndex;

    ScheduledExecutorService executor = newScheduledThreadPool(1);
    try {
      FluentFuture<?> f =
          FluentFuture.from(SettableFuture.create()).withTimeout(0, SECONDS, executor);
      ExecutionException e = assertThrows(ExecutionException.class, () -> f.get());
      assertThat(e).hasCauseThat().isInstanceOf(TimeoutException.class);
    } finally {
      executor.shutdown();
    }
  }

   * CacheLoader#reload} using {@code executor}.
   *
   * <p>This method is useful only when {@code loader.reload} has a synchronous implementation, such
   * as {@linkplain #reload the default implementation}.
   *
   * @since 17.0
   */
  @GwtIncompatible // Executor + Futures
  public static <K, V> CacheLoader<K, V> asyncReloading(
      CacheLoader<K, V> loader, Executor executor) {
    checkNotNull(loader);

      ListenableFuture<I> input,
      AsyncFunction<? super I, ? extends O> function,
      Executor executor) {
    AsyncTransformFuture<I, O> output = new AsyncTransformFuture<>(input, function);
    input.addListener(output, rejectionPropagatingExecutor(executor, output));
    return output;
  }

  static <I extends @Nullable Object, O extends @Nullable Object> ListenableFuture<O> create(

    @Override
    public String call() {
      return "foo";
    }
  }

  /** Simple same thread listening executor service that doesn't handle shutdown. */
  private static class TestListeningExecutorService extends AbstractListeningExecutorService {

    @Override
    public void execute(Runnable runnable) {
      assertThat(runnable).isInstanceOf(TrustedListenableFutureTask.class);
      runnable.run();
    }

  /**
   * @since 13.0
   */
  @Override
  public final void addListener(Listener listener, Executor executor) {
    listeners.addListener(listener, executor);
  }

  @Override
  public String toString() {
    return getClass().getSimpleName() + " [" + state() + "]";
  }

  /**
   * Attempts to execute all the listeners in {@link #listeners} while not holding the {@link
   * #monitor}.
   */

        CountDownLatch latch = new CountDownLatch(threadCount);
        AtomicInteger successCount = new AtomicInteger(0);
        ExecutorService executor = Executors.newFixedThreadPool(threadCount);

        for (int t = 0; t < threadCount; t++) {
            final int threadId = t;
            executor.submit(() -> {
                try {
                    for (int i = 0; i < operationsPerThread; i++) {

                .setSize(500)
                .setScroll(settings.getScrollTimeout())
                .setQuery(QueryBuilders.rangeQuery(freqField).gte(1))
                .execute()
                .actionGet(settings.getSearchTimeout());
        String scrollId = response.getScrollId();
        try {
            while (scrollId != null) {

import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import java.util.Collections;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;