client.delete(request, listener);
    }

    @Override
    public DeleteRequestBuilder prepareDelete() {
        return client.prepareDelete();
    }

    @Override
    public DeleteRequestBuilder prepareDelete(final String index, final String id) {
        return client.prepareDelete(index, id);
    }

    @Override
    public ActionFuture<BulkResponse> bulk(final BulkRequest request) {

    public HtmlResponse clearCrawlerIndex(final ActionForm form) {
        validate(form, messages -> {}, this::asIndexHtml);
        verifyToken(this::asIndexHtml);
        searchEngineClient.admin().indices().prepareDelete(//
                fessConfig.getIndexDocumentCrawlerIndex() + ".queue", //
                fessConfig.getIndexDocumentCrawlerIndex() + ".data", //
                fessConfig.getIndexDocumentCrawlerIndex() + ".filter")