I am finding that it would be useful to be able to define a dataclass that is an abstract base class and define some of its field as abstract.
As I am typing this, I realize that I could presumably write some code to implement what I'm asking for. Maybe it is a good enough idea to make part of the standard API in any case though? I'm thinking that a field would be made abstract by passing `abstract=True` as an argument to `dataclasses.field()`.
