{"ast_node_type":"variable","tokens":[{"end":27,"kind":"keyword","start":0,"text":"let"}]}
        let is_std_string =
        let string_type = self.tcx.lang_items().string();
            |ty: Ty<'tcx>| ty.ty_adt_def().is_some_and(|ty_def| Some(ty_def.did()) == string_type);