LazyList implements Cloneable, Serializable { public static String toString(Object list) { if (list == null) return "[]"; if (list instanceof List) return list.toString(); return "[" + list + "]"; } private  LazyList(); @SuppressWarnings("unchecked") static Object add(Object list, Object item); @SuppressWarnings("unchecked") static Object add(Object list, int index, Object item); static Object addCollection(Object list, Collection<?> collection); static Object addArray(Object list, Object[] array); static Object ensureSize(Object list, int initialSize); static Object remove(Object list, Object o); static Object remove(Object list, int i); static List<E> getList(Object list); @SuppressWarnings("unchecked") static List<E> getList(Object list, boolean nullForEmpty); static boolean hasEntry(Object list); static boolean isEmpty(Object list); static String[] toStringArray(Object list); static Object toArray(Object list, Class<?> clazz); static int size(Object list); @SuppressWarnings("unchecked") static E get(Object list, int i); static boolean contains(Object list, Object item); static Object clone(Object list); static String toString(Object list); @SuppressWarnings("unchecked") static Iterator<E> iterator(Object list); @SuppressWarnings("unchecked") static ListIterator<E> listIterator(Object list);  }
@Test void testToString_NullInput() { Object input = null; assertEquals("[]", LazyList.toString(input)); }
@Test void testToString_NonListInput() { String input = "a"; assertEquals("[a]", LazyList.toString(input)); }