def test_missingName(self):
        """
        If a name is missing, L{Resolver.lookupAddress} returns a L{Deferred}
        which fails with L{DNSNameError}.
        """
        servers = {
            ('1.1.2.3', 53): {
                (b'foo.example.com', A): {
                    'rCode': ENAME,
                    },
                },
            }
        resolver = self._getResolver(servers)
        d = resolver.lookupAddress(b'foo.example.com')
        return self.assertFailure(d, DNSNameError)

        If a name is missing, L{Resolver.lookupAddress} returns a L{Deferred}
        which fails with L{DNSNameError}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/names/test/test_rootresolve.py