### Question:
CollectionUtils { public static boolean isEmpty(Collection<?> col) { return !isNotEmpty(col); } private  CollectionUtils(); static boolean isEmpty(Collection<?> col); static boolean isNotEmpty(Collection<?> col); static boolean isEmpty(Object[] array); static boolean isNotEmpty(Object[] array); static String toString(Collection<?> col); static boolean isSizeEquals(Collection<?> col0, Collection<?> col1); static String encodeMap(Map<String, String> map); static Map<String, String> decodeMap(String data); static List<String> toUpperList(List<String> sourceList);  }### Answer:
@Test public void testIsEmptyWithArrays() { String[] emptyArray = {}; String[] filledArray = {"Foo", "Bar"}; Assertions.assertTrue(CollectionUtils.isEmpty(emptyArray)); Assertions.assertFalse(CollectionUtils.isEmpty(filledArray)); }
@Test public void testIsEmptyWithCollection() { List<String> emptyCollection = new ArrayList<>(); List<String> filledCollection = new ArrayList<>(); filledCollection.add("Foo"); filledCollection.add("Bar"); Assertions.assertTrue(CollectionUtils.isEmpty(emptyCollection)); Assertions.assertFalse(CollectionUtils.isEmpty(filledCollection)); }