content: import 'package:flutter/material.dart';
  
  void main() => runApp(MyApp());
  
  class MyApp extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return MaterialApp(
        title: 'Flutter Demo',
        theme: ThemeData(
          primarySwatch: Colors.blue,
        ),
        home: MyHomePage(),
      );
    }
  }
  
  class MyHomePage extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return Scaffold(
        body: CustomScrollView(
          slivers: <Widget>[
            SliverAppBar(
              floating: true,
              pinned: true,
              expandedHeight: 200.0,
              flexibleSpace: FlexibleSpaceBar(
                title: const Text('FlexibleSpaceBar'),
                centerTitle: true,
                background: Stack(
                  fit: StackFit.expand,
                  children: <Widget>[Image.asset('images/flutter_logo.png')],
                ),
              ),
            ),
            SliverList(
              delegate: SliverChildBuilderDelegate(
                (BuildContext context, int index) {
                  return ListTile(
                    title: Text('Item $index'),
                  );
                },
                childCount: 30,
              ),
            )
          ],
        ),
      );
    }
  }
  