@Override
    public void serialize(Asn1OutputStream out, Integer obj) {
        out.writeInt(obj);
    }
@Test
    public void shouldSerialize() {
        assertArrayEquals(
            new byte[] { 0x31, (byte) 0xab, (byte) 0xcd, (byte) 0xef },
            serialize(new IntegerConverter(), int.class, 0x31abcdef)
        );
    }