sparx5_lg_get_next
next = sparx5_lg_get_next(sparx5, layer, group, itr);
return idx == sparx5_lg_get_next(sparx5, layer, group, idx);
next = sparx5_lg_get_next(sparx5, layer, i, itr);
*next = sparx5_lg_get_next(sparx5, layer, group, itr);