anchor.diff:  
   class DebuggerScreen extends Screen {
     DebuggerScreen()
  -      : super(name: 'Debugger', id: 'debugger', iconClass: 'octicon-bug') {
  +      : debuggerState = new DebuggerState(),
  +        super(name: 'Debugger', id: 'debugger', iconClass: 'octicon-bug') {
       deviceStatus = new StatusItem();
       addStatusItem(deviceStatus);
  -
  -    serviceManager.onConnectionAvailable.listen(_handleConnectionStart);
  -    if (serviceManager.hasConnection) {
  -      _handleConnectionStart(serviceManager.service);
  -    }
  -    serviceManager.isolateManager.onSelectedIsolateChanged
  -        .listen(_handleIsolateChanged);
  -    serviceManager.onConnectionClosed.listen(_handleConnectionStop);
  -  }
  +  }
  +
  +  final DebuggerState debuggerState;
  +
  +  bool _initialized = false;
   
     StatusItem deviceStatus;
   
  
positive.code: 
        debuggerState.switchToIsolate(isolateRef);
  
        return;
      }
  
  
negative.code:   @override
    void createContent(Framework framework, CoreElement mainDiv) {
      CoreElement sourceArea;
  
      final PButton resumeButton = new PButton(null)
        ..primary()
  