{"ast_node_type":"other","tokens":[{"end":9,"kind":"keyword","start":0,"text":"{"}]}
        {
        let (builtin_name, helper_attrs) = match find_attr!(attrs, AttributeKind::RustcBuiltinMacro { builtin_name, helper_attrs, .. } => (builtin_name, helper_attrs))
            // Override `helper_attrs` passed above if it's a built-in macro,