ExpansionPanelList Flutter

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'ExpansionTile Collapse',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: TestExpandableView(),
    );
  }
}

class TestExpandableView extends StatefulWidget {
  @override
  _TestExpandableViewState createState() => _TestExpandableViewState();
}

class _TestExpandableViewState extends State<TestExpandableView> {
  int _activeMeterIndex;
  @override
  Widget build(BuildContext context) {
    return Container(
      width: 400,
      child: new ListView.builder(
          shrinkWrap: true,
          itemCount: 10,
          itemBuilder: (BuildContext context, int i) {
            return Card(
              elevation: 0,
              // margin: const EdgeInsets.fromLTRB(10.0, 15.0, 10.0, 0.0),
              child: new ExpansionPanelList(
                dividerColor: Colors.grey,
                expansionCallback: (int index, bool status) {
                  setState(() {
                    _activeMeterIndex = _activeMeterIndex == i ? null : i;
                  });
                },
                children: [
                  new ExpansionPanel(
                    isExpanded: _activeMeterIndex == i,
                    headerBuilder: (BuildContext context, bool isExpanded) =>
                        new Container(
                            padding: const EdgeInsets.only(left: 15.0),
                            alignment: Alignment.centerLeft,
                            child: new Text(
                              'Title-$i',
                            )),
                    body: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text('Details-$i'),
                      ],
                    ),
                  ),
                ],
              ),
            );
          }),
    );
  }
}