private void push(List<URL> urls) {
    if (!urls.isEmpty()) {
      synchronized (myUrls) {
        for (int i = urls.size() - 1; i >= 0; i--) {
          myUrls.add(urls.get(i));
        }
        myAllUrlsWereProcessed = false;
      }
    }
  }
private void push(List<URL> urls)