{"ast_node_type":"variable","tokens":[{"end":94,"kind":"keyword","start":0,"text":"let"}]}
        let use_format_args_since_1_89_0 = fmt_args().is_some() && fmt_unsafe_arg().is_none();
            || crate::lang_item::lang_item(self.db, self.module.krate(), LangItem::FormatUnsafeArg);