{"ast_node_type":"other","tokens":[{"end":31,"kind":"keyword","start":0,"text":"if"}]}
                if *s == succ {
                let s = other_to.chain.get_mut(in_to_index + 1).unwrap_or(&mut other_to.target);
                    // `other_to` references the `current -> succ` edge, so replace `succ`.