@classmethod
def get_from_collected_values(cls, contextual_vals, option_vals):
    """
        When the menu class also subclasses django.db.models.Model, this
        method is called by ``render_from_tag()`` to 'get' a menu object
        appropriate for the provided contextual and option values.
        """
    raise NotImplementedError(
        "Subclasses of 'Menu' and 'django.db.models.Model' must define their own 'get_from_collected_values' method."
        )
