def test_spf(self):
        """
        L{DNSServerFactory} can serve I{SPF} resource records.
        """
        return self.namesTest(
            self.resolver.lookupSenderPolicy('test-domain.com'),
            [dns.Record_SPF(b'v=spf1 mx/30 mx:example.org/30 -all',
                            ttl=19283784),
            dns.Record_SPF(b'v=spf1 +mx a:\0colo',
                           b'.example.com/28 -all not valid', ttl=19283784)]
        )

        L{DNSServerFactory} can serve I{SPF} resource records.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/names/test/test_names.py