}

    public static long scroll(final String index, final Function<SearchHit, Boolean> callback) {
        final SearchEngineClient client = ComponentUtil.getSearchEngineClient();
        return client.<SearchHit> scrollSearch(index, searchRequestBuilder -> true, (searchResponse, hit) -> hit,
                hit -> callback.apply(hit));
    }

    public static String getXContentString(final ToXContent xContent, final MediaType mediaType) {