* ListeningScheduledExecutorService}, it is returned untouched, and the rest of this
   * documentation does not apply.
   *
   * @since 10.0
   */
  @J2ktIncompatible
  @GwtIncompatible // TODO
  public static ListeningScheduledExecutorService listeningDecorator(
      ScheduledExecutorService delegate) {
    return (delegate instanceof ListeningScheduledExecutorService)
        ? (ListeningScheduledExecutorService) delegate

        new ScheduledThreadPoolExecutor(1) {
          @Override
          protected void afterExecute(Runnable r, Throwable t) {
            completed.countDown();
          }
        };
    ListeningScheduledExecutorService service = listeningDecorator(delegate);
    ListenableFuture<Integer> future = service.schedule(Callables.returning(42), 1, MILLISECONDS);

    /*

        new ScheduledThreadPoolExecutor(1) {
          @Override
          protected void afterExecute(Runnable r, Throwable t) {
            completed.countDown();
          }
        };
    ListeningScheduledExecutorService service = listeningDecorator(delegate);
    ListenableFuture<Integer> future = service.schedule(Callables.returning(42), 1, MILLISECONDS);

    /*