def test_arg_plistUnmatchedParentheses(self):
        """
        A parenthesized with unmatched parentheses raises
        L{IllegalClientResponse}.
        """
        self.assertRaises(imap4.IllegalClientResponse,
                          self.server.arg_plist, b"(foo")
        self.assertRaises(imap4.IllegalClientResponse,
                          self.server.arg_plist, b"foo)")

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