{"ast_node_type":"variable","tokens":[{"end":126,"kind":"keyword","start":0,"text":"let"}]}
                            let (value_hash, old_hash): (Fingerprint, Fingerprint) = tcx.with_stable_hashing_context(|mut hcx|
                        if let Some(hasher) = hasher {
                                (hasher(&mut hcx, &value), hasher(&mut hcx, &old))