class ListenableFutureTask extends FutureTask<V> implements ListenableFuture<V> {

    public static <V> ListenableFutureTask<V> create(Callable<V> callable) {
        return new ListenableFutureTask<V>(callable);
    }

      ListenableFutureTask(Callable<V> callable);
      ListenableFutureTask(Runnable runnable, V result);

}