{"ast_node_type":"variable","tokens":[{"end":57,"kind":"keyword","start":0,"text":"let"}]}
    let ty = fn_sig.output().fold_with(&mut type_folder);
    let mut type_folder = TransformTy::new(tcx, transform_ty_options);
    s.push_str(&encode_ty(tcx, ty, dict, encode_ty_options));