radix_first
for(n=radix_first(db->zonetree); n; n=radix_next(n)) {
struct radnode* radix_first(struct radtree* rt);
for(n=radix_first(nsd->db->zonetree); n; n=radix_next(n)) {
if(xfrs_processed) for( node = radix_first(nsd->db->zonetree)
for(n=radix_first(nsd->db->zonetree); n; n=radix_next(n)) {
node = radix_first(nsd->db->zonetree);