AbdealiLoKo

The `polymorphic_on` can be a CASE WHEN statement. Ref: https://docs.sqlalchemy.org/en/14/orm/mapping_api.html#sqlalchemy.orm.mapper.params.polymorphic_on But it looks like sqlalchemy-continuum fails when I try to add `__versioned__` to a model with it. ``` File "/home/abdealijk/venv/lib/python3.7/site-packages/sqlalchemy_continuum/builder.py",...

I was looking at the docs for [Enum._serialize](https://marshmallow.readthedocs.io/en/stable/marshmallow.fields.html#marshmallow.fields.Enum._serialize) and got confused by what it was saying: > Serializes value to a basic Python datatype. Noop by default And then realized...