def test_lookupAddress(self):
        """
        L{hosts.Resolver.lookupAddress} returns a L{Deferred} which fires with A
        records from the hosts file.
        """
        d = self.resolver.lookupAddress(b'multiple')
        def resolved(results):
            answers, authority, additional = results
            self.assertEqual(
                (RRHeader(b"multiple", A, IN, self.ttl,
                          Record_A("1.1.1.3", self.ttl)),
                 RRHeader(b"multiple", A, IN, self.ttl,
                          Record_A("1.1.1.4", self.ttl))),
                answers)
        d.addCallback(resolved)
        return d

        L{hosts.Resolver.lookupAddress} returns a L{Deferred} which fires with A
        records from the hosts file.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/names/test/test_hosts.py