{"ast_node_type":"variable","tokens":[{"end":71,"kind":"keyword","start":0,"text":"let"}]}
        let universe = self.universe_indices[index].unwrap_or_else(|| {
            self.universe_indices.len() + self.current_index.as_usize() - debruijn.as_usize() - 1;
            for i in self.universe_indices.iter_mut().take(index + 1) {