Iterables.addAll(queue, elements);
    return queue;
  }

  // SynchronousQueue

  /** Creates an empty {@code SynchronousQueue} with nonfair access policy. */
  @J2ktIncompatible
  @GwtIncompatible // SynchronousQueue
  public static <E> SynchronousQueue<E> newSynchronousQueue() {
    return new SynchronousQueue<>();
  }

  /**