{"ast_node_type":"variable","tokens":[{"end":50,"kind":"keyword","start":0,"text":"let"}]}
        let optgroups = config::rustc_optgroups();
        let filename = suspect.strip_prefix("-").unwrap_or(suspect);
        let fake_args = ["optimize", "o0", "o1", "o2", "o3", "ofast", "og", "os", "oz"];