def unknown_departure(self, node):
        if  (self.document.settings.strict_visitor
             or node.__class__.__name__ not in self.optional):
            raise NotImplementedError(
                '%s departing unknown node type: %s'
                % (self.__class__, node.__class__.__name__))
Called before exiting unknown `Node` types.
dataset/ETHPy150Open adieu/allbuttonspressed/docutils/nodes.py/NodeVisitor.unknown_departure