{"ast_node_type":"variable","tokens":[{"end":79,"kind":"keyword","start":0,"text":"let"}]}
        let derive = self.by_key(sym::rustc_builtin_macro).tt_values().next()?;
    pub fn parse_rustc_builtin_macro(&self) -> Option<(Name, Box<[Name]>)> {
        parse_macro_name_and_helper_attrs(derive)