CollectionUtils { public static boolean isEmpty(Collection<?> collection) { return collection == null || collection.isEmpty(); } private  CollectionUtils(); @SuppressWarnings({"unchecked", "rawtypes"}) static List<T> sort(List<T> list); static List<String> sortSimpleName(List<String> list); static Map<String, Map<String, String>> splitAll(Map<String, List<String>> list, String separator); static Map<String, List<String>> joinAll(Map<String, Map<String, String>> map, String separator); static Map<String, String> split(List<String> list, String separator); static List<String> join(Map<String, String> map, String separator); static String join(List<String> list, String separator); static boolean mapEquals(Map<?, ?> map1, Map<?, ?> map2); static Map<String, String> toStringMap(String... pairs); @SuppressWarnings("unchecked") static Map<K, V> toMap(Object... pairs); static boolean isEmpty(Collection<?> collection); static boolean isNotEmpty(Collection<?> collection);  }
@Test public void testIsEmpty() throws Exception { assertThat(isEmpty(null), is(true)); assertThat(isEmpty(new HashSet()), is(true)); assertThat(isEmpty(emptyList()), is(true)); }