queue.setParentUrl(parentUrl);
        assertEquals(parentUrl, queue.getParentUrl());

        queue.setParentUrl(null);
        assertNull(queue.getParentUrl());
    }

    public void test_depthGetterSetter() {
        // Test depth getter/setter
        UrlQueueImpl<Long> queue = new UrlQueueImpl<>();

        queue.setDepth(0);
        assertEquals(Integer.valueOf(0), queue.getDepth());