{"ast_node_type":"other","tokens":[{"end":71,"kind":"keyword","start":0,"text":"//"}]}
        // over `Fn*`, since all async closures implement `FnOnce`, but
        // HACK(async_closures): For async closures, prefer `AsyncFn*`
        // choosing that over `AsyncFn`/`AsyncFnMut` would be more restrictive.