- support slotted attrs classes? need to rethink init approach, currently just steals from and prunes
__dict__- necessary tho? realistic for model to have >thousands of packages? probably not..
- if so, will attrs-generated
__getstate__/__setstate__work?
- integrate with custom coordinate transform / range index?
- do we need any hooks? e.g.
__xattree_post_init__? - cache accessors at decoration time for faster
__getattr__at runtime - run converters/validators in
__setattr__override - type checking a la https://stackoverflow.com/a/50622643?