addon_after_class is ignored

[gofeel]

The document says addon_after_class will work, but there is no handling logics at all.

Note. Here is how django-bootstrap4 are handling it. https://github.com/zostera/django-bootstrap4/blob/adc99067b2459d1dafac9904db6f8748acaefe85/src/bootstrap4/renderers.py#L388

[larseggert]

I think I'm seeing the same issue.