@Test
public void test_canSetExistedDomain_canExpire_thenReLookupBack() throws Exception {

    final String domain = "github.com";
    Set<String> expected = getAllHostAddresses(domain);
    DnsCacheManipulator.setDnsCache(30, domain, IP3);
    assertEquals(IP3, InetAddress.getByName(domain).getHostAddress());
    sleep(32);
    assertEquals(expected, getAllHostAddresses(domain));
}