|  | // Copyright (c) 2020, 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. | 
|  |  | 
|  | // TODO(51557): Decide if the mixins being applied in this test should be | 
|  | // "mixin", "mixin class" or the test should be left at 2.19. | 
|  | // @dart=2.19 | 
|  |  | 
|  | void main() { | 
|  | ContentTabsWidget(); | 
|  | } | 
|  |  | 
|  | class StatefulWidget {} | 
|  |  | 
|  | class State<T> {} | 
|  |  | 
|  | class WidgetsBindingObserver {} | 
|  |  | 
|  | class IBase {} | 
|  |  | 
|  | class ContentTabsWidget extends BaseStatefulWidget<ContentTabsState, dynamic> {} | 
|  |  | 
|  | class ContentTabsState<W extends ContentTabsWidget> | 
|  | extends BaseState<W, dynamic> {} | 
|  |  | 
|  | class BaseStatefulWidget<ST extends SuperState, T> | 
|  | extends SuperStatefulWidget<ST, T, IBase> {} | 
|  |  | 
|  | class BaseState<W extends StatefulWidget, T> extends SuperState<W, T, IBase> {} | 
|  |  | 
|  | class SuperStatefulWidget<S extends SuperState, T, B> extends StatefulWidget {} | 
|  |  | 
|  | class SuperState<W extends StatefulWidget, T, B> extends State<W> | 
|  | with WidgetsBindingObserver {} |