/**
 * Transforms a value, possibly asynchronously. For an example usage and more information, see
 * {@link Futures#transformAsync(ListenableFuture, AsyncFunction, Executor)}.
 *
 * @author Chris Povirk
 * @since 11.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface AsyncFunction<I extends @Nullable Object, O extends @Nullable Object> {
  /**

  }

  /**
   * 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(

        }
      };

  private static <V> AsyncFunction<V, V> asyncIdentity() {
    return new AsyncFunction<V, V>() {
      @Override
      public ListenableFuture<V> apply(V input) {
        return immediateFuture(input);
      }
    };
  }

  private static <I, O> AsyncFunction<I, O> tagged(
      final String toString, final AsyncFunction<I, O> function) {
    return new AsyncFunction<I, O>() {

        }
      };

  private static <V> AsyncFunction<V, V> asyncIdentity() {
    return new AsyncFunction<V, V>() {
      @Override
      public ListenableFuture<V> apply(V input) {
        return immediateFuture(input);
      }
    };
  }

  private static <I, O> AsyncFunction<I, O> tagged(
      final String toString, final AsyncFunction<I, O> function) {
    return new AsyncFunction<I, O>() {

      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,

    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());

  /**
   * 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;