Doc error: line number is `None`

https://nbdev.fast.ai/api/doclinks.html#nbdevlookup.code:~:text=fastcore/net.py%23-,LNone,-%27
Why is the line number is `None` here but correct in rendered docs?

Open the linked nbdev API documentation and inspect the `nbdevlookup.code` reference for the `fastcore/net.py` source link. Compare the displayed `LNone` anchor with the line number used in the rendered documentation, then trace the documentation-link generation entry point. Done means the generated source link contains the correct line number rather than `None`.

Written by the indexing model from the issue text.