Tutorial for GNN Explainability--Code Example--problems

[gongchenghua]

https://diveintographs.readthedocs.io/en/latest/tutorials/subgraphx.html Hi! when I follow the code example, I find that in step 2: def check_checkpoints(root='./'): if osp.exists(osp.join(root, 'checkpoints')): return url = ('https://github.com/divelab/DIG_storage/raw/main/xgraph/checkpoints.zip') path = download_url(url, root) extract_zip(path, root) os.unlink(path) here download_url is not defined, so what should I do to solve the problems?