I have multiple classes annotated with `@Entity`. Half of the classes have these 3 additional fields in them: `specialFieldA`, `specialFieldB`, and `specialFieldC`; the other half do not.

Is there a JPA way to ensure that future classes have these 3 fields in them? I.e. if a teammate wants to make another class with `specialFieldA`, `specialFieldB`, and `specialFieldC` in them, is there a way to enforce having these 3 fields?

I thought of using an interface, but it didn't seem like the right strategy since you can only define methods. 

I can't use an abstract class because these classes already extend a parent class.