{"ast_node_type":"impl","tokens":[{"end":93,"kind":"keyword","start":0,"text":"//"}]}
        // `option::Option<T>::Xyz<impl Trait>` and reject `option::Option<impl Trait>::Xyz`.
        // Only permit `impl Trait` in the final segment. E.g., we permit `Option<impl Trait>`,
        let itctx = |i| {