AsyncDataWriter implements DataWriter<T> { @Override public Future<Boolean> isOutOfDate() { return Future.of(() -> comparator.isOutOfDate(), executorService); }  static AsyncDataWriter<T> asyncDataWriter(Executor executorService, ManifestComparator<T> comparator); static AsyncDataWriter<T> asyncDataWriter(Executor executorService, ManifestComparator<T> comparator,
            EventBus bus); @Override Future<T> loadAndGet(); @Override Future<Void> saveAndIncrement(T data); @Override Future<Boolean> isOutOfDate(); static final String MANIFEST_COMPARATOR_DATA_LOADER_KEY; static final String MANIFEST_COMPARATOR_DATA_WRITER_KEY; }
@Test public void testIsOutOfDate() { writer.isOutOfDate() .get(); assertThat(dummyMc.outofDateCalled.get(), equalTo(1)); }