def model_policy_volt(pk):
    # TODO: this should be made in to a real model_policy
    with transaction.atomic():
        volt = VOLTTenant.objects.select_for_update().filter(pk=pk)
        if not volt:
            return
        volt = volt[0]
        volt.manage_vcpe()
        volt.manage_subscriber()
        volt.cleanup_orphans()