ListView.builder inside another ListView.builder - flutter

Question

The listView.builder that is inside of the first, when i scroll the screen delete the data.
I used .insert that adds another widget inside the list.
in the first ListView.builder the data does not dissapear.
this what i do.
this is the first listView that keeps the data.
class _TestsPage extends State<TestsPage> with TickerProviderStateMixin {
final _commentController = TextEditingController();
bool _isWriting = false;
final List<CommentaryBox> _commentariBox = [];
#override
Widget build(BuildContext context) {
final model = Provider.of<Model>(context);
return DraggableScrollableSheet(
expand: false,
maxChildSize: 0.8,
initialChildSize: 0.6,
minChildSize: 0.6,
builder: (BuildContext context, ScrollController controller) => Column(
children: [
Expanded(
child: ListView.builder(
controller: controller,
physics: const BouncingScrollPhysics(),
itemBuilder: (_, i) => _commentariBox[i],
itemCount: _commentariBox.length,
//
reverse: false,
),
),
second listView.builder that delete data.
Visibility(
visible: _showComments,
child: ExpansionTile(
// initiallyExpanded: true,
title: _deployText
? Text('see less commentaries')
: Text('see commentaries'),
onExpansionChanged: (bool expanded) {
setState(
() {
_deployText = expanded;
},
);
},
children: [
ListView.builder(
physics: BouncingScrollPhysics(),
shrinkWrap: true,
itemBuilder: (_, i) => responseBox[i],
itemCount: responseBox.length,
reverse: true,
),
],
),
),
the way how I insert data to the list is the same for both
_handleResponse(String reply) {
final model = Provider.of<Model>(context, listen: false);
if (reply.isEmpty) return;
respController.clear();
final newAnswer = ResponseWidget(
reply: reply,
animationController: AnimationController(
vsync: this,
duration: Duration(milliseconds: 400),
),
);
responseBox.insert(0, newAnswer);
newAnswer.animationController.forward();
setState(() {
model.showComments= true;
});
}
}

Answer 1

I found the solution!
I just had to add this in my appState this: AutomaticKeepAliveClientMixin
in the constructor this:
#override
Widget build(BuildContext context) {
super.build(context);
and add the implemetation:
#override
// TODO: implement wantKeepAlive
bool get wantKeepAlive => true;