{"ast_node_type":"function","tokens":[{"end":64,"kind":"keyword","start":0,"text":"fn"}]}
    fn pre(&self, _state: &mut State<'_>, _node: AnnNode<'_>) {}
    fn nested(&self, _state: &mut State<'_>, _nested: Nested) {}
    fn post(&self, _state: &mut State<'_>, _node: AnnNode<'_>) {}