{"ast_node_type":"variable","tokens":[{"end":54,"kind":"keyword","start":0,"text":"if"}]}
                        if let Some(hasher) = hasher {
                        let old = restore::<$V>(old);
                            let (value_hash, old_hash): (Fingerprint, Fingerprint) = tcx.with_stable_hashing_context(|mut hcx|