class _PractState extends State<EnPract> {
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.blueGrey,
        title: Text('Practice Tests'),
      ),
      body: Stack(
        children: <Widget>[
          Container(
              width: 600,
              height: 850,
              child: Image.asset("assets/pencilbg.png",
                  fit: BoxFit.fill, alignment: Alignment.center)),
          ListView.builder(
            itemBuilder: (BuildContext context, int index) =>
                EntryItem(data[index]),
            itemCount: data.length,
          )
        ],
      ),
    );
  }
}

class EntryItem extends StatelessWidget {
  const EntryItem(this.entry);

  final Entry entry;

  Widget _buildTiles(Entry root) {
    if (root.children.isEmpty) return ListTile(title: Text(root.title), onTap: ,);
    return Card(
        elevation: 1,
        child: ExpansionTile(
          key: PageStorageKey<Entry>(root),
          title: Text(root.title),
          children: root.children.map<Widget>(_buildTiles).toList(),
        ));
  }

  @override
  Widget build(BuildContext context) {
    return _buildTiles(entry);
  }
}