Actually, the `lazy_attribute` will be instantiated before being passed in as a keyword argument to the `_create` method of the factory. `lazy_attribute` just means that rather than being an attribute value defined on the factory at class definition time, it's a function that has access to the rest of the class attributes defined (and is only called if not overridden). So, in summary, it's not called by virtue of being pulled from `kwargs`, but it's only called if the client instantiating the factory hasn't provided a `modulestore` parameter.