anchor.diff:        focusNode: FocusNode(),
         cursorColor: Colors.red,
         backgroundCursorColor: Colors.blue,
  -      style: Typography.material2018(platform: TargetPlatform.android).black.subtitle1.copyWith(fontFamily: 'Roboto'),
  +      style: Typography.material2018(platform: TargetPlatform.android).black.subtitle1!.copyWith(fontFamily: 'Roboto'),
         keyboardType: TextInputType.text,
         inputFormatters: <TextInputFormatter>[LengthLimitingTextInputFormatter(6)],
         onChanged: (String s) => controller.text += ' onChanged',
  
positive.code:               focusNode: FocusNode(),
                cursorColor: Colors.red,
                backgroundCursorColor: Colors.blue,
                style: Typography.material2018(platform: TargetPlatform.android).black.subtitle1.copyWith(fontFamily: 'Roboto'),
                keyboardType: TextInputType.text,
                inputFormatters: <TextInputFormatter>[LengthLimitingTextInputFormatter(6)],
              ),
  
negative.code: 
      testWidgets('input from changing controller', (WidgetTester tester) async {
        final TextEditingController controller = TextEditingController(text: testText);
        Widget build({ TextEditingController? textEditingController }) {
          return MediaQuery(
            data: const MediaQueryData(),
            child: Directionality(
  