Example:
```py
>>> from huggingface_hub import cached_assets_path  
>>> cached_assets_path(library_name="datasets", namespace="SQuAD", subfolder="download")
PosixPath('/home/wauplin/.cache/huggingface/extra/datasets/SQuAD/download')  
>>> cached_assets_path(library_name="datasets", namespace="SQuAD", subfolder="extracted")
PosixPath('/home/wauplin/.cache/huggingface/extra/datasets/SQuAD/extracted')  
>>> cached_assets_path(library_name="datasets", namespace="Helsinki-NLP/tatoeba_mt")