@Override
    public void register(URL url) {
        if (url == null) {
            throw new IllegalArgumentException("register url == null");
        }
        if (url.getPort() != 0) {
            if (logger.isInfoEnabled()) {
                logger.info("Register: " + url);
            }
        }
        registered.add(url);
    }
@Test
    void testRegister() {
        // test one url
        abstractRegistry.register(mockUrl);
        assert abstractRegistry.getRegistered().contains(mockUrl);
        // test multiple urls
        for (URL url : abstractRegistry.getRegistered()) {
            abstractRegistry.unregister(url);
        }
        List<URL> urlList = getList();
        for (URL url : urlList) {
            abstractRegistry.register(url);
        }
        MatcherAssert.assertThat(abstractRegistry.getRegistered().size(), Matchers.equalTo(urlList.size()));
    }