{"ast_node_type":"function","tokens":[{"end":90,"kind":"keyword","start":0,"text":"fn"}]}
    fn walk_unvisited_node(&mut self, initial: G::Node) -> WalkReturn<A::SccIdx, A::Ann> {
    #[instrument(skip(self, initial), level = "trace")]
        trace!("Walk unvisited node: {initial:?}");