anchor.diff:        await tester.pumpWidget(wrap(widget));
   
         final richText = findRichTextWidget(tester);
  -      expect(richText.text.text, isNull);
  -      expect(richText.text.children, [TextSpan(text: content)]);
  +      final textSpan = getTextSpan(richText);
  +      expect(textSpan.text, isNull);
  +      expect(textSpan.children, [TextSpan(text: content)]);
       });
   
       testWidgets('with tags', (tester) async {
  
positive.code:       await tester.pumpWidget(wrap(newWidget));
  
        final richText = findRichTextWidget(tester);
        expect(richText.text.text, isNull);
        expect(richText.text.children, [
          TextSpan(text: 'Hello, '),
          TextSpan(text: 'Bob', style: updatedStyle),
        ]);
  
negative.code:   return tester.widget(richTextFinder) as RichText;
  }
  
  TextSpan getTextSpan(RichText richText) {
    expect(richText.text, isA<TextSpan>());
    return richText.text as TextSpan;
  }
  
  Widget wrap(Widget widget) {
    return Directionality(
      textDirection: TextDirection.ltr,
  