def METHOD_NAME(self):
    schedules = self.get_queryset()
    query = self.kwargs.get(self.lookup_field)
    if query == "wip":
        schedule = schedules.filter(version__isnull=True).first()
    else:
        if query == "latest" and self.request.event.current_schedule:
            query = self.request.event.current_schedule.version
        schedule = schedules.filter(version__iexact=query).first()
    if not schedule:
        raise Http404
    return schedule