interface Facade<T> extends ListenableFuture<T> {
    @CanIgnoreReturnValue
    boolean set(T t);

    @CanIgnoreReturnValue
    boolean setException(Throwable t);
  }

  private static class NewAbstractFutureFacade<T> extends AbstractFuture<T> implements Facade<T> {
    @CanIgnoreReturnValue
    @Override
    public boolean set(T t) {
      return super.set(t);
    }

    @CanIgnoreReturnValue
    @Override