Rather than requiring changes to Django, I believe you can do this with a
MutationObserver to detect the class attribute changing on the
corresponding elements:
https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver/observe .
This has the advantage that we don't need to add custom events
When the admin's collapse script has finished it would be good to get an
event I can listen to:
https://github.com/django/django/blob/master/django/contrib/admin/static/admin/js/collapse.js
This would be useful for custom scripts that rely on the collapse class and
elements being in place. It wo
