_prop_stack_pop
while (_prop_stack_pop(&stack, &obj, &iter, &data, NULL)) {
while (_prop_stack_pop(&stack, &parent_obj, &iter, &data, NULL)) {
while (_prop_stack_pop(&stack, &obj, &iter, &data, NULL)) {
while (_prop_stack_pop(&stack, &parent_obj, &iter, &data, NULL)) {
} while (_prop_stack_pop(&stack, &obj, NULL, NULL, NULL));
if (!_prop_stack_pop(&stack, &obj1, &obj2,
while (_prop_stack_pop(&stack, &obj1, &obj2, NULL, NULL)) {
bool _prop_stack_pop(prop_stack_t, prop_object_t *, void **, void **, void **);