Result(Future<Object> result) {
      this.future = result;
    }
  }

  private enum ExceptionType {
    CHECKED(IOException.class),
    UNCHECKED(RuntimeException.class);

    final Class<? extends Exception> exceptionType;

    ExceptionType(Class<? extends Exception> exceptionType) {
      this.exceptionType = exceptionType;
    }
  }

  @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);
  }

  /**

   */
  @J2ktIncompatible
  @Partially.GwtIncompatible("AVAILABLE but requires exceptionType to be Throwable.class")
  public final <X extends Throwable> FluentFuture<V> catching(
      Class<X> exceptionType, Function<? super X, ? extends V> fallback, Executor executor) {
    return (FluentFuture<V>) Futures.catching(this, exceptionType, fallback, executor);
  }

  /**

      Class<X> exceptionType, ClosingFunction<? super X, ? extends V> fallback, Executor executor) {
    return catchingMoreGeneric(exceptionType, fallback, executor);
  }

  // Avoids generic type capture inconsistency problems where |? extends V| is incompatible with V.
  private <X extends Throwable, W extends V> ClosingFuture<V> catchingMoreGeneric(

      // getGenericExceptionTypes() will never return a type that's not exception
      @SuppressWarnings("unchecked")
      TypeToken<? extends Throwable> exceptionType =
          (TypeToken<? extends Throwable>) TypeToken.of(type);
      builder.add(exceptionType);
    }
    return builder.build();
  }

  /**
   * Explicitly specifies the return type of this {@code Invokable}. For example:
   *

      Class<X> exceptionType, ClosingFunction<? super X, ? extends V> fallback, Executor executor) {
    return catchingMoreGeneric(exceptionType, fallback, executor);
  }

  // Avoids generic type capture inconsistency problems where |? extends V| is incompatible with V.
  private <X extends Throwable, W extends V> ClosingFuture<V> catchingMoreGeneric(