code: public boolean addAll(int[] items) {
      ensureCapacity(size + items.length);
      for (int i = 0; i < items.length; i++) {
        elements[size++] = items[i];
      }
      return items.length > 0;
    }
docs: Appends a range of values to the end of this array.
  
  @param items
  The values to append.
  @return A value indicating if the array has changed.