### Question:
CollectionUtils { public static boolean isNullOrEmpty(Collection<?> input) { return input == null || input.isEmpty(); } private  CollectionUtils(); static ArrayList<L> filter(List<L> list, Predicate<L> predicate); static ArrayList<T> map(List<G> input, Function1<T, G> function); static Set<T> map(Set<G> input, Function1<T, G> function); static boolean isNullOrEmpty(Collection<?> input); static List<Integer> asList(int... ids); static Set<T> asSet(T... items);  }### Answer:
@Test public void isNullOrEmpty() { final List<String> strings = Arrays.asList("a", "aa", "aaa", "aaaa"); Assert.assertFalse(CollectionUtils.isNullOrEmpty(strings)); Assert.assertTrue(CollectionUtils.isNullOrEmpty(null)); Assert.assertTrue(CollectionUtils.isNullOrEmpty(Collections.emptyList())); }