import java.util.concurrent.Future;
import org.jspecify.annotations.Nullable;

/**
 * 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
public interface AsyncFunction<I extends @Nullable Object, O extends @Nullable Object> {
  /**

  }

  @SuppressWarnings("FutureTransformAsync") // We intentionally test transformAsync.
  public void testTransformAsync_genericsWildcard_asyncFunction() throws Exception {
    ListenableFuture<?> nullFuture = immediateVoidFuture();
    ListenableFuture<?> chainedFuture =
        transformAsync(nullFuture, x -> immediateFuture("hi"), directExecutor());
    assertThat(getDone(chainedFuture)).isEqualTo("hi");

  }

  @SuppressWarnings("FutureTransformAsync") // We intentionally test transformAsync.
  public void testTransformAsync_genericsWildcard_asyncFunction() throws Exception {
    ListenableFuture<?> nullFuture = immediateVoidFuture();
    ListenableFuture<?> chainedFuture =
        transformAsync(nullFuture, x -> immediateFuture("hi"), directExecutor());
    assertThat(getDone(chainedFuture)).isEqualTo("hi");

        };
    return derive(state.future.transformAsync(applyFunction, executor));
  }

  /**
   * Returns an {@link AsyncClosingFunction} that applies an {@link AsyncFunction} to an input,
   * ignoring the DeferredCloser and returning a {@code ClosingFuture} derived from the returned
   * {@link ListenableFuture}.
   *
   * <p>Use this method to pass a transformation to {@link #transformAsync(AsyncClosingFunction,

    assertClosed(closeable1, closeable2);
  }

  public void testTransformAsync() throws Exception {
    ClosingFuture<String> closingFuture =
        ClosingFuture.from(immediateFuture("value"))
            .transformAsync(
                (DeferredCloser closer, String v) -> {
                  closer.eventuallyClose(closeable1, closingExecutor);
                  closer.eventuallyClose(closeable2, closingExecutor);

    assertThat(f.get()).isEqualTo(2);
  }

  public void testTransformAsync() throws Exception {
    FluentFuture<Integer> f =
        FluentFuture.from(immediateFuture(1))
            .transformAsync(i -> immediateFuture(i + 1), directExecutor());
    assertThat(f.get()).isEqualTo(2);
  }

  @J2ktIncompatible
  @GwtIncompatible // withTimeout
  public void testWithTimeout() throws Exception {

   *     input's failure (if not)
   */
  public final <T extends @Nullable Object> FluentFuture<T> transformAsync(
      AsyncFunction<? super V, T> function, Executor executor) {
    return (FluentFuture<T>) Futures.transformAsync(this, function, executor);
  }

  /**
   * Returns a new {@code Future} whose result is derived from the result of this {@code Future}. If

   * Example usage:
   *
   * {@snippet :
   * ListenableFuture<RowKey> rowKeyFuture = indexService.lookUp(query);
   * ListenableFuture<QueryResult> queryFuture =
   *     transformAsync(rowKeyFuture, dataService::readFuture, executor);
   * }
   *
   * <p>When selecting an executor, note that {@code directExecutor} is dangerous in some cases. See

          // setFuture, so a user couldn't break the chain by doing this themselves.  It is also
          // potentially common if someone writes a recursive Futures.transformAsync transformer.
          future = setFuture.owner;
          if (future.value() == setFuture) {
            Object valueToSet = getFutureValue(setFuture.future);
            if (casValue(future, setFuture, valueToSet)) {