/**
   * This counter prevents an ABA issue where a thread may successfully schedule the worker, the
   * worker runs and exhausts the queue, another thread enqueues a task and fails to schedule the
   * worker, and then the first thread's call to delegate.execute() returns. Without this counter,
   * it would observe the QUEUING state and set it to QUEUED, and the worker would never be
   * scheduled again for future submissions.
   */
  @GuardedBy("queue")

  @Override
  public void setUp() {
    threadPool = newCachedThreadPool();
  }

  @Override
  public void tearDown() throws InterruptedException {
    threadPool.shutdown();
    assertTrue("Some worker didn't finish in time", threadPool.awaitTermination(10, SECONDS));
  }

  private static <T> int drain(
      BlockingQueue<T> q,
      Collection<? super T> buffer,
      int maxElements,
      long timeout,

  @Override
  public void setUp() {
    threadPool = newCachedThreadPool();
  }

  @Override
  public void tearDown() throws InterruptedException {
    threadPool.shutdown();
    assertTrue("Some worker didn't finish in time", threadPool.awaitTermination(10, SECONDS));
  }

  private static <T> int drain(
      BlockingQueue<T> q,
      Collection<? super T> buffer,
      int maxElements,
      long timeout,

   *
   * <p>{@linkplain Executor#execute executed} tasks have a happens-before order as defined in the
   * Java Language Specification. Tasks execute with the same happens-before order that the function
   * calls to {@link Executor#execute `execute()`} that submitted those tasks had.
   *
   * <p>The executor uses {@code delegate} in order to {@link Executor#execute execute} each task in

    public static final String UNSAFE_URL = "unsafe-url";
  }

  /**
   * The HTTP <a href="https://www.w3.org/TR/service-workers/#update-algorithm">{@code
   * Service-Worker}</a> header field name.
   *
   * @since 20.0
   */
  public static final String SERVICE_WORKER = "Service-Worker";
  /** The HTTP {@code TE} header field name. */
  public static final String TE = "TE";

     * that could call it, nor exposed this Future for users to call cancel() on).
     */
    requireNonNull(futures);

    // Corner case: List is empty.
    if (futures.isEmpty()) {
      handleAllCompleted();
      return;
    }

    // NOTE: If we ever want to use a custom executor here, have a look at CombinedFuture as we'll