anchor.diff:        });
   
         testWidgets('expansion_panels_demo $themeName', (WidgetTester tester) async {
  +        final AutomatedTestWidgetsFlutterBinding binding = tester.binding;
  +        binding.addTime(const Duration(seconds: 3));
           final SemanticsHandle handle = tester.ensureSemantics();
           await tester.pumpWidget(MaterialApp(theme: theme, home: ExpansionPanelsDemo()));
           await expectLater(tester, meetsGuideline(textContrastGuideline));
  
positive.code:       });
  
        testWidgets('buttons_demo $themeName', (WidgetTester tester) async {
          final SemanticsHandle handle = tester.ensureSemantics();
          await tester.pumpWidget(MaterialApp(theme: theme, home: ButtonsDemo()));
          await expectLater(tester, meetsGuideline(textContrastGuideline));
  
negative.code:       });
  
        testWidgets('progress_indicator_demo $themeName', (WidgetTester tester) async {
          final AutomatedTestWidgetsFlutterBinding binding = tester.binding;
          binding.addTime(const Duration(seconds: 3));
          final SemanticsHandle handle = tester.ensureSemantics();
          await tester.pumpWidget(MaterialApp(theme: theme, home: ProgressIndicatorDemo()));
          await expectLater(tester, meetsGuideline(textContrastGuideline));
  