def destroy(self):
        """
        Destroy all lanes in this network
        Returns: None

        """
        super(NodeRoadNetwork, self).destroy()
        if self.graph is not None:
            for from_, _to_dict in self.graph.items():
                for _to, lanes in _to_dict.items():
                    for lane in lanes:
                        lane.destroy()
            self.graph = None

        Destroy all lanes in this network
        Returns: None

        
metadrive/component/road_network/node_road_network.py