@Override
    public String toString() {
        return toStringHelper(getClass())
                .add("targetAddress", Arrays.toString(targetAddress))
                .toString();
        // TODO: need to handle options
    }
@Test
    public void testToStringNS() throws Exception {
        NeighborSolicitation ns = deserializer.deserialize(bytePacket, 0, bytePacket.length);
        String str = ns.toString();

        // TODO: need to handle TARGET_ADDRESS and Options
    }