def test_recordMissing(self):
        """
        If a L{FileAuthority} has a zone which includes an I{NS} record for a
        particular name and that authority is asked for another record for the
        same name which does not exist, the I{NS} record is not included in the
        authority section of the response.
        """
        authority = NoFileAuthority(
            soa=(str(soa_record.mname), soa_record),
            records={
                str(soa_record.mname): [
                    soa_record,
                    dns.Record_NS('1.2.3.4'),
                    ]})
        d = authority.lookupAddress(str(soa_record.mname))
        result = []
        d.addCallback(result.append)
        answer, authority, additional = result[0]
        self.assertEqual(answer, [])
        self.assertEqual(
            authority, [
                dns.RRHeader(
                    str(soa_record.mname), soa_record.TYPE,
                    ttl=soa_record.expire, payload=soa_record,
                    auth=True)])
        self.assertEqual(additional, [])

        If a L{FileAuthority} has a zone which includes an I{NS} record for a
        particular name and that authority is asked for another record for the
        same name which does not exist, the I{NS} record is not included in the
        authority section of the response.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/names/test/test_names.py