check_CT_CLEAR(const struct ofpact_null *a OVS_UNUSED,
               const struct ofpact_check_params *cp OVS_UNUSED)
{
    return 0;
}
check_CT_CLEAR(const struct ofpact_null *a OVS_UNUSED,
               const struct ofpact_check_params *cp OVS_UNUSED)
{
    return 0;
}