{"ast_node_type":"other","tokens":[{"end":57,"kind":"keyword","start":0,"text":"expr_to_spanned_string(cx,"}]}
    expr_to_spanned_string(cx, expr, err_msg).map(|res| {
) -> ExpandResult<Result<(Symbol, ast::StrStyle), ErrorGuaranteed>, ()> {
        res.map_err(|err| match err {