anchor.diff:      }
   
       test('bool extension', () async {
  -      final extensionDescription = extensions.debugPaint;
  +      const extensionDescription = extensions.debugPaint;
         final args = {'enabled': true};
         const evalExpression = 'debugPaintSizeEnabled';
         final library = new EvalOnDartLibrary(
  
positive.code:     });
  
      test('numeric extension', () async {
        final extensionDescription = extensions.slowAnimations;
        final args = {
          extensionDescription.extension
                  .substring(extensionDescription.extension.lastIndexOf('.') + 1):
  
negative.code:     });
  
      test('String extension', () async {
        const extensionDescription = extensions.togglePlatformMode;
        final args = {'value': 'iOS'};
        const evalExpression = 'defaultTargetPlatform.toString()';
        final library = new EvalOnDartLibrary(
  