{"ast_node_type":"other","tokens":[{"end":74,"kind":"keyword","start":0,"text":"//"}]}
        // ...or *ideally*, we just have `LendingFn`/`LendingFnMut`, which
        // `Fn > AsyncFn > FnMut > AsyncFnMut > FnOnce > AsyncFnOnce`
        // would naturally unify these two trait hierarchies in the most