@Override
    protected void doRefresh(final List<MetaData> dataList) {
        metaDataSubscribers.forEach(MetaDataSubscriber::refresh);
        dataList.forEach(metaData -> metaDataSubscribers.forEach(metaDataSubscriber -> metaDataSubscriber.onSubscribe(metaData)));
    }
@Test
    public void testDoRefresh() {
        List<MetaData> metaDataList = createFakeMetaDataObjects(3);
        metaDataHandler.doRefresh(metaDataList);
        subscribers.forEach(subscriber -> verify(subscriber).refresh());
        metaDataList.forEach(metaData ->
                subscribers.forEach(subscriber -> verify(subscriber).onSubscribe(metaData)));
    }