range_tree_find
range_seg_t *addr_rs = range_tree_find(rt, start,
range_seg_t *addr_rs = range_tree_find(rt, start, size);
range_seg_t *rs = range_tree_find(rt, off, size);
return (range_tree_find(rt, start, size) != NULL);
range_seg_t *range_tree_find(range_tree_t *rt, uint64_t start, uint64_t size);