}
            }
        }
    }

    protected CrawlerClient getClient(final String url) {
        return clientFactory.getClient(url);
    }

    protected boolean isContentUpdated(final CrawlerClient client, final UrlQueue<?> urlQueue) {
        if (urlQueue.getLastModified() != null) {

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

    protected StreamResponse writeContent(final String configId, final String url, final CrawlerClient client) {