{"ast_node_type":"variable","tokens":[{"end":54,"kind":"keyword","start":0,"text":"let"}]}
            let (min_version, span) = match &mis[..] {
            try_gate_cfg(sym::version, cfg.span, sess, features);
                [MetaItemInner::Lit(MetaItemLit { kind: LitKind::Str(sym, ..), span, .. })] => {