@Test
    public void testSort() throws Exception {
        List<Integer> integers = new ArrayList<>();
        Collections.addAll(integers, 3, 0, 2, 0, 0, 2, 2);

        new IntegerArrayCountingSorter(3).sort(integers);

        assertThat(integers.toString(), is("[0, 0, 0, 2, 2, 2, 3]"));
    }