public boolean addAll(final IntArrayList list)
    {
        @DoNotSub final int numElements = list.size;
        if (numElements > 0)
        {
            ensureCapacityPrivate(size + numElements);
            System.arraycopy(list.elements, 0, elements, size, numElements);
            size += numElements;
            return true;
        }
        return false;
    }
@Test
    void shouldCreateObjectRefArray()
    {
        final int count = 20;
        final List<Integer> expected = new ArrayList<>();
        IntStream.range(0, count).forEachOrdered(expected::add);
        list.addAll(expected);

        assertArrayEquals(expected.toArray(), list.toArray());
    }