code: public boolean addAll(int index, float[] items) {
      if (index < 0 || index > size) {
        throw new IndexOutOfBoundsException();
      }
      ensureCapacity(size + items.length);
      if (index < size) {
        for (int i = size - 1; i >= index; i--) {
          elements[i + items.length] = elements[i];
        }
      }
      for (float e : items) {
        elements[index++] = e;
      }
      size += items.length;
      return items.length > 0;
    }
docs: Inserts values into the array at the specified index.
  
  @param index
  The index at which to insert the new values.
  @param items
  An array of values to insert.
  @return A value indicating if the array has changed.
  @throws IndexOutOfBoundsException
  if <code>index &lt; 0 || index &gt; size()</code>.