{"ast_node_type":"variable","tokens":[{"end":90,"kind":"keyword","start":0,"text":"let"}]}
                    let is_err = if it.is_raw.no() && matches!(expr, ExprKind::Expr2021) {
                Some(TtElement::Leaf(tt::Leaf::Ident(it))) => {
                        it.sym == sym::underscore || it.sym == sym::let_ || it.sym == sym::const_