def create_lazy_user(self):
        """ Create a lazy user. Returns a 2-tuple of the underlying User
        object (which may be of a custom class), and the username.
        """
        user_class = self.model.get_user_class()
        username = self.generate_username(user_class)
        user = user_class.objects.create_user(username, '')
        self.create(user=user)
        return user, username
Create a lazy user. Returns a 2-tuple of the underlying User
        object (which may be of a custom class), and the username.