// Copyright (c) 2017, 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

/// @assertion final bool keys
/// @description Check that [keys] is a read-only property.
/// @author iarkh@unipro.ru

import "dart:collection";
import "../../../Utils/expect.dart";

main() {
  dynamic view = new UnmodifiableMapView(
      {1 : 1, 2 : 23, 37 : 49});
  Expect.throws(() { view.keys = null; }, (e) => e is NoSuchMethodError);
}