@GwtCompatible
@J2ktIncompatible // Super-sourced
abstract class GwtFuturesCatchingSpecialization {
  /*
   * This server copy of the class is empty. The corresponding GWT copy contains alternative
   * versions of catching() and catchingAsync() with slightly different signatures from the ones
   * found in Futures.java.
   */

    return (FluentFuture<V>) Futures.catching(this, exceptionType, fallback, executor);
  }

  public final FluentFuture<V> catchingAsync(
      Class<Throwable> exceptionType,
      AsyncFunction<? super Throwable, ? extends V> fallback,
      Executor executor) {
    return (FluentFuture<V>) Futures.catchingAsync(this, exceptionType, fallback, executor);
  }

@GwtCompatible
@J2ktIncompatible // Super-sourced
abstract class GwtFuturesCatchingSpecialization {
  /*
   * This server copy of the class is empty. The corresponding GWT copy contains alternative
   * versions of catching() and catchingAsync() with slightly different signatures from the ones
   * found in Futures.java.
   */

      Executor executor) {
    return AbstractCatchingFuture.create(input, exceptionType, fallback, executor);
  }

  public static <V extends @Nullable Object> ListenableFuture<V> catchingAsync(
      ListenableFuture<? extends V> input,
      Class<Throwable> exceptionType,
      AsyncFunction<? super Throwable, ? extends V> fallback,
      Executor executor) {

  }

  public void testCatchingAsync() throws Exception {
    FluentFuture<?> f =
        FluentFuture.from(immediateFailedFuture(new CustomRuntimeException()))
            .catchingAsync(
                Throwable.class,
                new AsyncFunction<Throwable, Class<?>>() {
                  @Override
                  public ListenableFuture<Class<?>> apply(Throwable input) {