@CheckForNull @LazyInit Class<X> exceptionType;
  @CheckForNull @LazyInit F fallback;

  AbstractCatchingFuture(
      ListenableFuture<? extends V> inputFuture, Class<X> exceptionType, F fallback) {
    this.inputFuture = checkNotNull(inputFuture);
    this.exceptionType = checkNotNull(exceptionType);
    this.fallback = checkNotNull(fallback);
  }

  @Override

  @Partially.GwtIncompatible("AVAILABLE but requires exceptionType to be Throwable.class")
  public static <V extends @Nullable Object, X extends Throwable> ListenableFuture<V> catching(
      ListenableFuture<? extends V> input,
      Class<X> exceptionType,
      Function<? super X, ? extends V> fallback,
      Executor executor) {
    return AbstractCatchingFuture.create(input, exceptionType, fallback, executor);
  }

  /**

  @Partially.GwtIncompatible("AVAILABLE but requires exceptionType to be Throwable.class")
  public static <V extends @Nullable Object, X extends Throwable> ListenableFuture<V> catching(
      ListenableFuture<? extends V> input,
      Class<X> exceptionType,
      Function<? super X, ? extends V> fallback,
      Executor executor) {
    return AbstractCatchingFuture.create(input, exceptionType, fallback, executor);
  }

  /**