def test_reprFlagsIfSet(self):
        """
        L{dns._EDNSMessage.__repr__} displays flags if they are L{True}.
        """
        m = self.messageFactory(answer=True, auth=True, trunc=True, recDes=True,
                                recAv=True, authenticData=True,
                                checkingDisabled=True, dnssecOK=True)
        self.assertEqual(
            '<_EDNSMessage '
            'id=0 '
            'flags=answer,auth,trunc,recDes,recAv,authenticData,'
            'checkingDisabled,dnssecOK'
            '>',
            repr(m),
        )

        L{dns._EDNSMessage.__repr__} displays flags if they are L{True}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/names/test/test_dns.py