def add_identity_override(self):  # type: ignore[no-untyped-def]
        """
        Add an identity override to the dataclass.

        This special method is here to simplify null checking logic.
        """
        if self.num_identity_overrides is None:
            self.num_identity_overrides = 1
        else:
            self.num_identity_overrides += 1

        Add an identity override to the dataclass.

        This special method is here to simplify null checking logic.
        
api/features/dataclasses.py