{"ast_node_type":"variable","tokens":[{"end":67,"kind":"keyword","start":0,"text":"let"}]}
        let cond = self.parse_expr_cond(policy).map_err(|mut err| {
        let policy = LetChainsPolicy::EditionDependent { current_edition: lo.edition() };
            err.span_label(lo, "while parsing the condition of this `while` expression");