### Question:
UrlUtils { public static URL getEmptyUrl(String service, String category) { String group = null; String version = null; int i = service.indexOf('/'); if (i > 0) { group = service.substring(0, i); service = service.substring(i + 1); } i = service.lastIndexOf(':'); if (i > 0) { version = service.substring(i + 1); service = service.substring(0, i); } return URL.valueOf(Constants.EMPTY_PROTOCOL + ": + Constants.CATEGORY_KEY + "=" + category + (group == null ? "" : "&" + Constants.GROUP_KEY + "=" + group) + (version == null ? "" : "&" + Constants.VERSION_KEY + "=" + version)); }  static URL parseURL(String address, Map<String, String> defaults); static List<URL> parseURLs(String address, Map<String, String> defaults); static Map<String, Map<String, String>> convertRegister(Map<String, Map<String, String>> register); static Map<String, String> convertSubscribe(Map<String, String> subscribe); static Map<String, Map<String, String>> revertRegister(Map<String, Map<String, String>> register); static Map<String, String> revertSubscribe(Map<String, String> subscribe); static Map<String, Map<String, String>> revertNotify(Map<String, Map<String, String>> notify); static List<String> revertForbid(List<String> forbid, Set<URL> subscribed); static URL getEmptyUrl(String service, String category); static boolean isMatchCategory(String category, String categories); static boolean isMatch(URL consumerUrl, URL providerUrl); static boolean isMatchGlobPattern(String pattern, String value, URL param); static boolean isMatchGlobPattern(String pattern, String value); static boolean isServiceKeyMatch(URL pattern, URL value); static URL getRegisterURL(String key); static URL getZkUrlByAddress(String addresses, String id, String serviceIp, Integer servicePort); static List<URL> getAllProviderRegisterURLs();  }### Answer:
@Test public void getEmptyUrl() throws Exception { }