*/
@ElementTypesAreNonnullByDefault
public interface ListenableFuture<V extends @Nullable Object> extends Future<V>, IThenable<V> {
  void addListener(Runnable listener, Executor executor);

  /** Note that this method is not expected to be overridden. */
  @JsMethod
  @Override
  default <R extends @Nullable Object> IThenable<R> then(

   * after executing them.
   *
   * @param listener the listener to run when the computation is complete
   * @param executor the executor to run the listener in
   * @throws RejectedExecutionException if we tried to execute the listener immediately but the
   *     executor rejected it.
   */
  void addListener(Runnable listener, Executor executor);

   * after executing them.
   *
   * @param listener the listener to run when the computation is complete
   * @param executor the executor to run the listener in
   * @throws RejectedExecutionException if we tried to execute the listener immediately but the
   *     executor rejected it.
   */
  void addListener(Runnable listener, Executor executor);