* ListenableFuture}</a>.
 *
 * <p>This class is GWT-compatible.
 *
 * <h3>Purpose</h3>
 *
 * <p>The main purpose of {@code ListenableFuture} is to help you chain together a graph of
 * asynchronous operations. You can chain them together manually with calls to methods like {@link
 * Futures#transform(ListenableFuture, com.google.common.base.Function, Executor) Futures.transform}

 * ListenableFuture}</a>.
 *
 * <p>This class is GWT-compatible.
 *
 * <h3>Purpose</h3>
 *
 * <p>The main purpose of {@code ListenableFuture} is to help you chain together a graph of
 * asynchronous operations. You can chain them together manually with calls to methods like {@link
 * Futures#transform(ListenableFuture, com.google.common.base.Function, Executor) Futures.transform}

import jsinterop.annotations.JsType;
import org.jspecify.annotations.Nullable;

/**
 * Java super source for ListenableFuture, implementing a structural thenable via a default method.
 * For restrictions, please refer to the documentation of the then() method.
 */
public interface ListenableFuture<V extends @Nullable Object> extends Future<V>, IThenable<V> {
  void addListener(Runnable listener, Executor executor);

public interface ListeningExecutorService extends ExecutorService {
  /**
   * @return a {@code ListenableFuture} representing pending completion of the task
   * @throws RejectedExecutionException {@inheritDoc}
   */
  @Override
  <T extends @Nullable Object> ListenableFuture<T> submit(Callable<T> task);

  /**
   * @return a {@code ListenableFuture} representing pending completion of the task
   * @throws RejectedExecutionException {@inheritDoc}

  private interface Merger {

    ListenableFuture<List<String>> merged(ListenableFuture<String> a, ListenableFuture<String> b);

    Merger allMerger =
        new Merger() {
          @Override
          public ListenableFuture<List<String>> merged(
              ListenableFuture<String> a, ListenableFuture<String> b) {
            return allAsList(ImmutableSet.of(a, b));
          }

  private interface Merger {

    ListenableFuture<List<String>> merged(ListenableFuture<String> a, ListenableFuture<String> b);

    Merger allMerger =
        new Merger() {
          @Override
          public ListenableFuture<List<String>> merged(
              ListenableFuture<String> a, ListenableFuture<String> b) {
            return allAsList(ImmutableSet.of(a, b));
          }

  private static final String DATA1 = "data";

  public void testListenInPoolThreadReturnsSameFuture() throws Exception {
    ListenableFuture<String> listenableFuture = immediateFuture(DATA1);
    assertThat(listenInPoolThread(listenableFuture)).isSameInstanceAs(listenableFuture);
  }

  private static class SingleCallListener implements Runnable {

    private boolean expectCall = false;

    - If users want only ListenableFuture, they depend on listenablefuture-1.0.

    - If users want all of Guava, they depend on guava, which, as of Guava
    27.0, depends on
    listenablefuture-9999.0-empty-to-avoid-conflict-with-guava. The 9999.0-...
    version number is enough for some build systems (notably, Gradle) to select
    that empty artifact over the "real" listenablefuture-1.0 -- avoiding a

    - If users want all of Guava, they depend on guava, which, as of Guava
    27.0, depends on
    listenablefuture-9999.0-empty-to-avoid-conflict-with-guava. The 9999.0-...
    version number is enough for some build systems (notably, Gradle) to select
    that empty artifact over the "real" listenablefuture-1.0 -- avoiding a

  private static final String DATA1 = "data";

  public void testListenInPoolThreadReturnsSameFuture() throws Exception {
    ListenableFuture<String> listenableFuture = immediateFuture(DATA1);
    assertThat(listenInPoolThread(listenableFuture)).isSameInstanceAs(listenableFuture);
  }

  private static class SingleCallListener implements Runnable {

    private boolean expectCall = false;