def pre_save_polymorphic(self):
        if not self.polymorphic_ctype_id:
            self.polymorphic_ctype = ContentType.objects.get_for_model(self, for_concrete_model=False)
Normally not needed.
dataset/ETHPy150Open chrisglass/django_polymorphic/polymorphic/models.py/PolymorphicModel.pre_save_polymorphic