@Test(expected = IllegalArgumentException.class)
 public void testIllegalArgumentException2() {
   IpAddressBuilder.getDefaultInstance("2001:0DB8::CD3/60");
 }
 private static void testIpv6(final String ip) {
   final IpAddress defaultInstance = IpAddressBuilder.getDefaultInstance(ip);
   assertEquals(new IpAddress(new Ipv6Address(ip)), defaultInstance);
 }
 @Test(expected = IllegalArgumentException.class)
 public void testIllegalArgumentException1() {
   IpAddressBuilder.getDefaultInstance("badIp");
 }