### Question:
CollectionUtils { public static boolean mapEquals(Map<?, ?> map1, Map<?, ?> map2) { if (map1 == null && map2 == null) { return true; } if (map1 == null || map2 == null) { return false; } if (map1.size() != map2.size()) { return false; } for (Map.Entry<?, ?> entry : map1.entrySet()) { Object key = entry.getKey(); Object value1 = entry.getValue(); Object value2 = map2.get(key); if (!objectEquals(value1, value2)) { return false; } } return true; } 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); static boolean isEmptyMap(Map map); static boolean isNotEmptyMap(Map map);  }### Answer:
@Test public void testMapEquals() throws Exception { assertTrue(CollectionUtils.mapEquals(null, null)); assertFalse(CollectionUtils.mapEquals(null, new HashMap<String, String>())); assertFalse(CollectionUtils.mapEquals(new HashMap<String, String>(), null)); assertTrue(CollectionUtils.mapEquals(CollectionUtils.toStringMap("1", "a", "2", "b"), CollectionUtils.toStringMap("1", "a", "2", "b"))); assertFalse(CollectionUtils.mapEquals(CollectionUtils.toStringMap("1", "a"), CollectionUtils.toStringMap("1", "a", "2", "b"))); }