def test_arg_flaglistMismatchedParentehses(self):
        """
        A list of flags with unmatched parentheses raises
        L{imap4.IllegalClientResponse}.
        """
        self.assertRaises(
            imap4.IllegalClientResponse,
            self.server.arg_flaglist, b"(invalid",
        )

        A list of flags with unmatched parentheses raises
        L{imap4.IllegalClientResponse}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/test/test_imap.py