sas_rp_tree_insert
sas_rp_tree_insert(&rproot, rpnode) != 0) {
if (sas_rp_tree_insert(&rproot, rpnode) != 0) {
(void) sas_rp_tree_insert(&(*rproot)->child, rpnode);
ret = sas_rp_tree_insert(&(*rproot)->child, rpnode);
ret = sas_rp_tree_insert(&(*rproot)->sibling,
sas_rp_tree_insert(rp_tree_t **rproot, rp_tree_t *rpnode);