def go_to_ticket(self, ticketid=None):
        """Surf to the page for the given ticket ID, or to the NewTicket page
        if `ticketid` is not specified or is `None`. If `ticketid` is
        specified, it assumes the ticket exists."""
        if ticketid is not None:
            ticket_url = self.url + ticketid % '/ticket/%s'
        else:
            ticket_url = self.url + '/newticket'
        self.go_to_url(ticket_url)
        tc.url(ticket_url + '$')
dataset/ETHPy150Open edgewall/trac/trac/tests/functional/tester.py/FunctionalTester.go_to_ticket/swapped operands of `%`