int idset_sch_contains(struct idset *set, struct subchannel_id id);
int idset_sch_get_first(struct idset *set, struct subchannel_id *id);
int idset_is_empty(struct idset *set);
int idset_sch_contains(struct idset *set, struct subchannel_id id);
int idset_sch_get_first(struct idset *set, struct subchannel_id *id);
int idset_is_empty(struct idset *set);