return httpClient.execute(httpRequest, new BasicHttpContext(httpClientContext));
    }

    /** Thread-local SimpleDateFormat for parsing non-standard date formats */
    private static final ThreadLocal<SimpleDateFormat> DATE_FORMAT_HOLDER =
            ThreadLocal.withInitial(() -> new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z", Locale.ENGLISH));

    /**
     * Parses the last modified date from a string value.

            buf.append(obj);
        } else if (obj instanceof Boolean) {
            buf.append(obj.toString());
        } else if (obj instanceof Date) {
            final SimpleDateFormat sdf = new SimpleDateFormat(CoreLibConstants.DATE_FORMAT_ISO_8601_EXTEND, Locale.ROOT);
            buf.append('\"').append(StringEscapeUtils.escapeJson(sdf.format(obj))).append('\"');
        } else {

        return httpClient.executeOpen(null, httpRequest, httpClientContext);
    }

    /** Thread-local SimpleDateFormat for parsing non-standard date formats */
    private static final ThreadLocal<SimpleDateFormat> DATE_FORMAT_HOLDER =
            ThreadLocal.withInitial(() -> new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z", Locale.ENGLISH));

    /** RFC 1123 date formatter */

        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 {