long counter = 0;
            final Deque<CrawlRequest> requestQueue = new LinkedList<>();
            final Set<String> processedUrls = new HashSet<>();
            requestQueue.offer(new CrawlRequest(url, 0));
            while (!requestQueue.isEmpty() && (maxAccessCount < 0 || counter < maxAccessCount)) {
                final CrawlRequest crawlRequest = requestQueue.poll();