if (logger.isDebugEnabled()) {
                logger.debug("Failed to process a scroll request.", e);
            }
            writeJsonResponse(HttpServletResponse.SC_BAD_REQUEST, e);
        } catch (final Exception e) {
            if (logger.isDebugEnabled()) {
                logger.debug("Failed to process a scroll request.", e);
            }

    /**
     * Get the value for the key 'api.search.scroll'. <br>
     * The value is, e.g. false <br>
     * comment: Whether to enable scroll for API search.
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getApiSearchScroll();

    /**
     * Is the property for the key 'api.search.scroll' true? <br>
     * The value is, e.g. false <br>

        final String index = "fess_basic_config";
        final ZipEntry entry = new ZipEntry(id + "/fess_basic_config.bulk");
        try {
            zos.putNextEntry(entry);
            SearchEngineUtil.scroll(index, hit -> {
                final String data = "{\"index\":{\"_index\":\"" + index + "\",\"_id\":\"" + StringEscapeUtils.escapeJson(hit.getId())
                        + "\"}}\n" + hit.getSourceAsString() + "\n";