code: @Beta
    @GwtIncompatible
    public static <T> AsyncCallable<T> asAsyncCallable(
        final Callable<T> callable, final ListeningExecutorService listeningExecutorService) {
      checkNotNull(callable);
      checkNotNull(listeningExecutorService);
      return new AsyncCallable<T>() {
        @Override
        public ListenableFuture<T> call() throws Exception {
          return listeningExecutorService.submit(callable);
        }
      };
    }
docs: Creates an {@link AsyncCallable} from a {@link Callable}.
  
  <p>The {@link AsyncCallable} returns the {@link ListenableFuture} resulting from {@link
  ListeningExecutorService#submit(Callable)}.
  
  @since 20.0