public static byte[] plus(byte[] in, int add) {
        if (in.length == 0) return in;

        final byte[] out = in.clone();
        add(out, add);
        return out;
    }
@Test
    public void plusNormal() {
        assertArrayEquals(new byte[] { 1, 2, 4}, ByteArrayUtils.plus(new byte[] { 1, 2, 3}, 1));
    }