// TODO date
        // lang
        if (StringUtil.isNotBlank(fessConfig.getCrawlerDocumentFileDefaultLang())) {
            putResultDataBody(dataMap, fessConfig.getIndexFieldLang(), fessConfig.getCrawlerDocumentFileDefaultLang());
        }
        // id
        putResultDataBody(dataMap, fessConfig.getIndexFieldId(), crawlingInfoHelper.generateId(dataMap));

     * The value is, e.g.  <br>
     * comment: Default language for file documents.
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getCrawlerDocumentFileDefaultLang();

    /**
     * Get the value for the key 'crawler.document.file.default.lang' as {@link Integer}. <br>
     * The value is, e.g.  <br>
     * comment: Default language for file documents.