private void addPagingUrl(Set<URL> urlSet) throws RuntimeException {
		int pageNo = config.getMaxPageNo();
		Set<URL> pagingSet = new HashSet<URL>();
		for (URL url : urlSet) {
			String urlStr = url.toFullString();
			while (pageNo >= 0) {
				String pageKey = config.getNextPageRegex().substring(0, config.getNextPageRegex().length() - 1)
						+ pageNo;
				String target = urlStr.replace(config.getNextPageRegex(), pageKey);
				pagingSet.add(URL.valueOf(target));
				pageNo--;
			}
		}
		urlSet.addAll(pagingSet);
	}