boolean visited(QUEUE urlQueue);

    /**
     * Generates URL queues.
     *
     * @param previousSessionId The previous session ID.
     * @param sessionId The session ID.
     */
    void generateUrlQueues(String previousSessionId, String sessionId);

     * Generates URL queues from a previous session's access results.
     * @param previousSessionId The previous session ID.
     * @param sessionId The current session ID.
     */
    @Override
    public void generateUrlQueues(final String previousSessionId, final String sessionId) {
        final Queue<UrlQueueImpl<Long>> urlQueueList = dataHelper.getUrlQueueList(sessionId);