code: public static <T> List<T> addAll(int index, List<T> list, T... array)
      {
          for (T item : array)
          {
              list.add(index++, item);
          }
          return list;
      }
docs: Add arrays members to list starting at index.
  <p>
  If list contains a,b,c,d and array 1,2,3. After addAll(2, list, array)
  list contains a,b,1,2,3,c,d
  @param <T>
  @param index
  @param list
  @param array