}
        doc.put(fessConfig.getResponseFieldUrlLink(), getUrlLink(doc));
        String createdStr;
        final Date created = DocumentUtil.getValue(doc, fessConfig.getIndexFieldCreated(), Date.class);
        if (created != null) {
            final SimpleDateFormat sdf = new SimpleDateFormat(CoreLibConstants.DATE_FORMAT_ISO_8601_EXTEND);
            createdStr = sdf.format(created);
        } else {

     * comment: Field name for creation date in the index.
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getIndexFieldCreated();

    /**
     * Get the value for the key 'index.field.timestamp'. <br>
     * The value is, e.g. timestamp <br>
     * comment: Field name for timestamp in the index.