def test_opt_datetimeMissingCloseQuote(self):
        """
        A line that does not have a closing double quote (C{"}) raises
        L{imap4.IllegalClientResponse}.
        """
        line = b'"21-Jul-2017 19:37:07 -0700'
        self.assertRaises(imap4.IllegalClientResponse,
                          self.server.opt_datetime, line)

        A line that does not have a closing double quote (C{"}) raises
        L{imap4.IllegalClientResponse}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/test/test_imap.py