* {@link Futures#transformAsync(ListenableFuture, AsyncFunction, Executor)}.
 *
 * @author Chris Povirk
 * @since 11.0
 */
@GwtCompatible
@FunctionalInterface
@ElementTypesAreNonnullByDefault
public interface AsyncFunction<I extends @Nullable Object, O extends @Nullable Object> {
  /**

      super(inputFuture, function);
    }

    @Override
    ListenableFuture<? extends O> doTransform(
        AsyncFunction<? super I, ? extends O> function, @ParametricNullness I input)
        throws Exception {
      ListenableFuture<? extends O> outputFuture = function.apply(input);
      checkNotNull(
          outputFuture,

  }

  /**
   * An {@link AbstractCatchingFuture} that delegates to an {@link AsyncFunction} and {@link
   * #setFuture(ListenableFuture)}.
   */
  private static final class AsyncCatchingFuture<V extends @Nullable Object, X extends Throwable>
      extends AbstractCatchingFuture<
          V, X, AsyncFunction<? super X, ? extends V>, ListenableFuture<? extends V>> {
    AsyncCatchingFuture(

      Class<X> exceptionType,
      final AsyncClosingFunction<? super X, W> fallback,
      Executor executor) {
    checkNotNull(fallback);
    AsyncFunction<X, W> asyncFunction =
        new AsyncFunction<X, W>() {
          @Override
          public ListenableFuture<W> apply(X exception) throws Exception {
            return closeables.applyAsyncClosingFunction(fallback, exception);
          }

      Executor executor) {
    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);
  }

  }

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

  /**
   * Returns a {@code Future} whose result is taken from this {@code Future} or, if this {@code
   * Future} fails with the given {@code exceptionType}, from the result provided by the {@code
   * fallback}. {@link AsyncFunction#apply} is not invoked until the primary input has failed, so if
   * the primary input succeeds, it is never invoked. If, during the invocation of {@code fallback},

import java.util.concurrent.CancellationException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;

/**
 * Unit tests for {@link Futures#transformAsync(ListenableFuture, AsyncFunction, Executor)}.
 *
 * @author Nishant Thakkar
 */
public class FuturesTransformAsyncTest extends AbstractChainedListenableFutureTest<String> {
  protected static final int SLOW_OUTPUT_VALID_INPUT_DATA = 2;

    FluentFuture<?> f =
        FluentFuture.from(immediateFailedFuture(new CustomRuntimeException()))
            .catchingAsync(
                Throwable.class,
                new AsyncFunction<Throwable, Class<?>>() {
                  @Override
                  public ListenableFuture<Class<?>> apply(Throwable input) {
                    return Futures.<Class<?>>immediateFuture(input.getClass());

import java.util.concurrent.CancellationException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;

/**
 * Unit tests for {@link Futures#transformAsync(ListenableFuture, AsyncFunction, Executor)}.
 *
 * @author Nishant Thakkar
 */
public class FuturesTransformAsyncTest extends AbstractChainedListenableFutureTest<String> {
  protected static final int SLOW_OUTPUT_VALID_INPUT_DATA = 2;