pkg/front_end/testcases/extension_types/issue53123.dart

// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

extension type V<T extends V<T>>(T id) {}

test(V v) {
  List<V> l = [v];
}