@classmethod
def create_from_collected_values(cls, contextual_vals, option_vals):
    """
        When the menu class in not model-based, this method is called by
        ``render_from_tag()`` to 'create' a menu object appropriate
        for the provided contextual and option values.
        """
    raise NotImplementedError(
        "Subclasses of 'Menu' must define their own 'create_from_collected_values' method."
        )
