Persist previously folded code when opening a notebook

Hi, I’ve been googling around but have not found an answer yet. I’m wondering if there is a way to persist folded code in notebooks so that when you save and re-open the notebook you don’t have to go through and re-fold classes/functions which were previously folded the last time you saved the notebook.

If this feature is not currently implemented/available, I’m wondering why? Is it that there have not been enough requests for this or is there some good justification for not persisting folded code?

Thank you!