def _render_confirm(self, req, milestone):
        req.perm(milestone.resource).require('MILESTONE_DELETE')

        milestones = [m for m in Milestone.select(self.env)
                      if m.name != milestone.name
                      and req.perm(m.resource) in 'MILESTONE_VIEW']
        attachments = Attachment.select(self.env, self.realm, milestone.name)
        data = {
            'milestone': milestone,
            'milestone_groups': group_milestones(milestones,
                'TICKET_ADMIN' in req.perm),
            'num_tickets': milestone.get_num_tickets(),
            'retarget_to': self.default_retarget_to,
            'attachments': list(attachments)
        }
        add_stylesheet(req, 'common/css/roadmap.css')
        return 'milestone_delete.html', data, None
dataset/ETHPy150Open edgewall/trac/trac/ticket/roadmap.py/MilestoneModule._render_confirm/swapped operands of `in`