Needs a test and documentation update, not just the docstring.

@ZeroIntensity thanks for your interest and I agree. I'm happy to take this to completion if there is buy-in from the CPython project. Before a new direction from @vsajip at #133577 any more changes here seems to be at risk of ending up in the trash can. Can you help me clear up the situation? Is this feature welcome or not? I would rather be sure first, and then go all in.

I'm not at liberty to approve the feature, but I'm personally +1. I defer to @vsajip.

Before a new direction from @vsajip

I'll look favorably on the change where you pass in a formatter instance rather than a class, as that is more generally useful than your earlier suggestion. Please go ahead and update the documentation and tests, as suggested by @ZeroIntensity.

@vsajip cool! Pushed, looking forward to your readme 🙏