{"ast_node_type":"variable","tokens":[{"end":76,"kind":"keyword","start":0,"text":"let"}]}
                let res = Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper);
            .map(|(_, ident)| {
                let binding = self.arenas.new_pub_res_binding(res, ident.span, expn_id);