@Override
    public String toString() {
        return toStringHelper(getClass())
                .add("routerFlag", Byte.toString(routerFlag))
                .add("solicitedFlag", Byte.toString(solicitedFlag))
                .add("overrideFlag", Byte.toString(overrideFlag))
                .add("targetAddress", Arrays.toString(targetAddress))
                .toString();
    }
@Test
    public void testToStringNA() throws Exception {
        NeighborAdvertisement na = deserializer.deserialize(bytePacket, 0, bytePacket.length);
        String str = na.toString();

        assertTrue(StringUtils.contains(str, "routerFlag=" + (byte) 1));
        assertTrue(StringUtils.contains(str, "solicitedFlag=" + (byte) 1));
        assertTrue(StringUtils.contains(str, "overrideFlag=" + (byte) 1));
        // TODO: need to handle TARGET_ADDRESS
    }