def METHOD_NAME(self):
    d = super().METHOD_NAME()
    d['rules'] = CheckinList.validate_rules(d.get('rules'))
    if d.get('addon_match') and d.get('all_products'):
        raise ValidationError(_('If you allow checking in add-on tickets by scanning the main ticket, you must '
                                'select a specific set of products for this check-in list, only including the '
                                'possible add-on products.'))
    return d