response.setHeaders(con.getHeaderFields());
            } catch (final Exception e) {
                throw new CurlException("Failed to access the response.", e);
            }
            writeContent(() -> {
                try {
                    if (con.getResponseCode() < 400) {
                        if (GZIP.equals(con.getContentEncoding())) {

        final CrawlerClient client = crawlerClientFactory.getClient(url);
        if (client == null) {
            throw new FessSystemException("No CrawlerClient: " + configId + ", url: " + url);
        }
        return writeContent(configId, url, client);
    }

    /**
     * Writes content from a crawler client to a stream response.
     *
     * @param configId the configuration ID
     * @param url the document URL