anchor.diff:      }
     }
   
  -  Widget buildPageStatus(
  +  Widget? buildPageStatus(
       BuildContext context,
       Screen currentScreen,
       TextTheme textTheme,
  
positive.code: }
  
  class IsolateSelector extends StatelessWidget {
    const IsolateSelector({Key key}) : super(key: key);
  
    @override
    Widget build(BuildContext context) {
      final textTheme = Theme.of(context).textTheme;
      final IsolateManager isolateManager = serviceManager.isolateManager;
      return DualValueListenableBuilder<List<IsolateRef>, IsolateRef>(
        firstListenable: isolateManager.isolates,
        secondListenable: isolateManager.selectedIsolate,
        builder: (context, isolates, selectedIsolateRef, _) {
  
negative.code: 
      children.add(const BulletSpacer());
  
      // Display an isolate selector.
      children.add(
        ValueListenableBuilder<bool>(
          valueListenable: currentScreen.showIsolateSelector,
          builder: (context, showIsolateSelector, _) {
            return showIsolateSelector
                ? Flexible(
                    child: Row(
                      children: const [
                        Expanded(
                          child: Center(
                            child: IsolateSelector(),
                          ),
                        ),
                        BulletSpacer(),
                      ],
                    ),
                  )
                : Container();
          },
        ),
      );
  
      // Display page specific status.
      final Widget? pageStatus =
          buildPageStatus(context, currentScreen, textTheme);
  
      if (pageStatus != null) {
        children.add(Expanded(
          child: Align(
            child: buildPageStatus(context, currentScreen, textTheme),
          ),
        ));
  
        children.add(const BulletSpacer());
      }
  
      // Always display connection status (docked to the right).
  