return ComponentUtil.getFessConfig().getIndexDocumentCrawlerIndex() + ".queue";
    }

    @Override
    public String getDataIndex() {
        return ComponentUtil.getFessConfig().getIndexDocumentCrawlerIndex() + ".data";
    }

    @Override
    public String getFilterIndex() {
        return ComponentUtil.getFessConfig().getIndexDocumentCrawlerIndex() + ".filter";
    }

    @Override

        verifyToken(this::asIndexHtml);
        searchEngineClient.admin().indices().prepareDelete(//
                fessConfig.getIndexDocumentCrawlerIndex() + ".queue", //
                fessConfig.getIndexDocumentCrawlerIndex() + ".data", //
                fessConfig.getIndexDocumentCrawlerIndex() + ".filter")
                .execute(ActionListener.wrap(res -> logger.info("Deleted .crawler indices."),

     * The value is, e.g. fess_crawler <br>
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getIndexDocumentCrawlerIndex();

    /**
     * Get the value for the key 'index.document.crawler.queue.number_of_shards'. <br>
     * The value is, e.g. 10 <br>