{"ast_node_type":"function","tokens":[{"end":84,"kind":"keyword","start":0,"text":"fn"}]}
        fn successors(&self, node: Self::Node) -> impl Iterator<Item = Self::Node> {
    impl<G: Successors + Predecessors> Successors for AsUndirected<G> {
            self.0.successors(node).chain(self.0.predecessors(node))