return scheduledDelegate.compareTo(other);
      }
    }

    @GwtIncompatible // TODO
    private static final class NeverSuccessfulListenableFutureTask
        extends AbstractFuture.TrustedFuture<@Nullable Void> implements Runnable {
      private final Runnable delegate;

      NeverSuccessfulListenableFutureTask(Runnable delegate) {
        this.delegate = checkNotNull(delegate);
      }