content: import 'package:flutter/material.dart';
  
  main() => runApp(new PersistentBottomSheetWidgetWidget());
  
  class PersistentBottomSheetWidgetWidget extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return new MaterialApp(
        title: 'Test',
        home: new Scaffold(
          appBar: new AppBar(title: new Text('Flutter UI Widget -- BottomSheet')),
          body: Builder(
            builder: (context) {
              return RaisedButton(
                onPressed: () {},
                child: Text('showBottomSheet'),
              );
            },
          ),
          bottomSheet: BottomSheet(
              onClosing: () {},
              builder: (context) => Container(
                    height: 200.0,
                    color: Colors.blue,
                    child: Center(
                      child: RaisedButton(
                        onPressed: () {
                          Navigator.of(context).pop();
                        },
                        child: Text('dismissBottomSheet'),
                      ),
                    ),
                  )),
        ),
      );
    }
  }
  