assertTrue(displayLinks.containsAll(customProv2.getLinksForDisplay()));
// writing url links as a string works
+ // because UrlProvider does not guarantee order of links, we can't just
+ // compare the output of writeUrlsAsString to a string, hence the hoops here
String result = customProv.writeUrlsAsString();
UrlProviderI up = new CustomUrlProvider(result);
assertTrue(displayLinks.containsAll(up.getLinksForDisplay()));