{"ast_node_type":"other","tokens":[{"end":82,"kind":"keyword","start":0,"text":"(hasher(&mut"}]}
                                (hasher(&mut hcx, &value), hasher(&mut hcx, &old))
                            let (value_hash, old_hash): (Fingerprint, Fingerprint) = tcx.with_stable_hashing_context(|mut hcx|
                            );