// Copyright 2015 The Chromium Authors. All rights reserved. | |
// Use of this source code is governed by a BSD-style license that can be | |
// found in the LICENSE file. | |
abstract class Key { | |
const factory Key(String value) = ValueKey<String>; | |
const Key._(); | |
} | |
abstract class LocalKey extends Key { | |
const LocalKey() : super._(); | |
} | |
class ValueKey<T> extends LocalKey { | |
final T value; | |
const ValueKey(this.value); | |
} |