protected int computeCount() {
        int c = 0;
        for (byte b : map) {
            c += Integer.bitCount(b & 0xFF);
        }

        return length - c;
    }
@Test
    public void testComputeCount() {
        LinearCounting lc = new LinearCounting(4);
        lc.offer(0);
        lc.offer(1);
        lc.offer(2);
        lc.offer(3);
        lc.offer(16);
        lc.offer(17);
        lc.offer(18);
        lc.offer(19);
        assertEquals(27, lc.computeCount());
    }