var _container = Container(
  height: 200,
  color: Colors.blue,
  margin: EdgeInsets.symmetric(vertical: 10),
);

@override
Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(title: Text("ListView")),
    body: Padding(
      padding: const EdgeInsets.all(40.0),
      child: ListView( // parent ListView
        children: [
          _container,
          _container,
          Container(
            height: 200, // give it a fixed height constraint
            color: Colors.teal,
            // child ListView
            child: ListView.builder(itemBuilder: (_, i) => ListTile(title: Text("Item ${i}"))),
          ),
          _container,
          _container,
          _container,
        ],
      ),
    ),
  );
}