This doesn't seem to have the desired effect: https://21369-1385122-gh.circle-artifacts.com/0/home/circleci/project/doc/build/html/gallery/widgets/span_selector.html

But even if the "note"-box appeared, would you want it to cut the code in half? Maybe use normal inline comments? Or put the note outside the code, such that it is still copy-pastable as a single entity?

Btw. I guess this note would then need to appear in all the widget examples?

As argued in #10876 (comment) / #10908 (comment) I think CallbackRegistry should just keep strong references...

I was trying to cut the code in half, but will go back to just in-line comments.

@tacaswell Let me know when you fix the rendering issue?

@timhoffm Does merging this mean that you will take the responsibility to make sure the note actually appears in a future PR?

It was an improvement in any case. I'm sure someone will at some point see this, and open a PR to fix it.

@ImportanceOfBeingErnest I was a bit quick. Assuming you mean #14422.