{"ast_node_type":"variable","tokens":[{"end":81,"kind":"keyword","start":0,"text":"let"}]}
        let typing_env = ty::TypingEnv::post_analysis(tcx, body.source.def_id());
        // to runtime, so we have to manually specify the correct typing mode.
        let can_const_prop = CanConstProp::check(tcx, typing_env, body);