{"ast_node_type":"variable","tokens":[{"end":66,"kind":"keyword","start":0,"text":"let"}]}
            let ExpnId { krate: cnum, local_id: index } = expn_id;
        let expn_id = rustc_span::hygiene::decode_expn_id(cnum, index, |expn_id| {
            // Lookup local `ExpnData`s in our own crate data. Foreign `ExpnData`s