def _autoregister(self, model, follow=None):
        """Registers a model with reversion, if required."""
        if not self.revision_manager.is_registered(model):
            follow = follow and []
            # Use model_meta.concrete_model to catch proxy models
            for parent_cls, field in model._meta.concrete_model._meta.parents.items():
                follow.append(field.name)
                self._autoregister(parent_cls)
            self.revision_manager.register(model, follow=follow, format=self.reversion_format)
dataset/ETHPy150Open etianen/django-reversion/src/reversion/admin.py/VersionAdmin._autoregister/operator `or` -> `and`