check(2 == s.size(), "There should be 2 items, not " + s.size());
check(s.containsAll(Generic.list(rand, v)));
check(!s.containsAll(Generic.list(rand, v, "other")));
check(s.retainAll(Generic.list(rand)));
check(!s.retainAll(Generic.list(rand)));
check(s.addAll(Generic.list(rand, v)));
check(2 == s.size(), "There should be 2 items, not " + s.size());
check(!s.addAll(Generic.list(rand, v)));
check(2 == s.size(), "There should be 2 items, not " + s.size());
}