def get_product_variant(self, extra):
        msg = "Method get_product_variant(extra) must be implemented by subclass: `{}`"
        raise NotImplementedError(msg.format(self.__class__.__name__))
Get a variant of the product or itself, if the product has no flavors.
dataset/ETHPy150Open awesto/django-shop/example/myshop/models/polymorphic/product.py/Product.get_product_variant