pkg/front_end/testcases/extensions/extension_constructor.dart

// Copyright (c) 2019, 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.
// @dart=2.9
class Class {}

extension Extension on Class {
  Extension() {}
  Extension.named() {}
  factory Extension.fact() => null;
  factory Extension.redirect() = Extension;

  method() {}
}

main() {}