Java Utililty Methods List Value Add All

if (array == null) {
    return;
list.addAll(Arrays.asList(array));

for (final E value : values) {
    list.add(value);

final List<T> result = new ArrayList<>(firstList);
result.addAll(secondList);
return result;

for (final T element : elements) {
    list.add(element);

for (T item : array) {
    list.add(index++, item);
return list;

return addAll(dest, src, true);

addAll(fromList, toList, false);

int count = elements.length;
for (int i = 0; i < count; i++) {
    list.add(elements[i]);

for (String item : array)
    list.add(item);

return addElements(list, array);