scf_iter_snaplevel_pgs
ret = scf_iter_snaplevel_pgs(iter, cur_level);
if (scf_iter_snaplevel_pgs(iter, level) != SCF_SUCCESS)
if (scf_iter_snaplevel_pgs(imp_up_iter, snpl) != 0) {
int scf_iter_snaplevel_pgs(scf_iter_t *, const scf_snaplevel_t *);