@dataclass(frozen=True, slots=True)
class C:
    i: int

C(10).j = 5

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 5, in __setattr__
TypeError: super(type, obj): obj must be an instance or subtype of type

@dataclass(frozen=True, slots=True)
class C:
    i: int

class D(C):
    pass

D(10).j = 5