assertFalse(urlSet.contains("http://example0.com/robots.txt")); // First one should be evicted
    }

    /**
     * Test activeThreadCountLock getter
     */
    public void test_activeThreadCountLock() {
        Object lock = crawlerContext.getActiveThreadCountLock();
        assertNotNull(lock);

        // Should return same instance
        Object sameLock = crawlerContext.getActiveThreadCountLock();