def test_expiredTTLLookup(self):
        r = ([dns.RRHeader("example.com", dns.A, dns.IN, 60,
                           dns.Record_A("127.0.0.1", 60))],
             [dns.RRHeader("example.com", dns.A, dns.IN, 50,
                           dns.Record_A("127.0.0.1", 50))],
             [dns.RRHeader("example.com", dns.A, dns.IN, 40,
                           dns.Record_A("127.0.0.1", 40))])

        clock = task.Clock()
        # Make sure timeouts never happen, so entries won't get cleared:
        clock.callLater = lambda *args, **kwargs: None

        c = cache.CacheResolver({
            dns.Query(name="example.com", type=dns.A, cls=dns.IN) :
                (clock.seconds(), r)}, reactor=clock)

        clock.advance(60.1)

        return self.assertFailure(
            c.lookupAddress("example.com"), dns.DomainError)
When the cache is queried exactly as the cached entry should expire but
dataset/ETHPy150Open nlloyd/SubliminalCollaborator/libs/twisted/names/test/test_cache.py/Caching.test_expiredTTLLookup