How To Make Vertical Radio Button In Flutter Android App

import 'dart:async';
import 'package:flutter/material.dart';
void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(
        primarySwatch: Colors.green,
      ),
      home: MyHomePage(),
      debugShowCheckedModeBanner: false,
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
  @override
  String radioItem = '';

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.indigo,
        title: Text('Vertical custom Radio Button'),
      ),
      body: Column(
        mainAxisAlignment: MainAxisAlignment.start,
        children: [
          RadioListTile(
            activeColor: Colors.indigo,
            groupValue: radioItem,
            title: Text('Abc',style: TextStyle(color: Colors.black54,fontSize:15)),
            value: 'Item 1',
            onChanged: (val) {
              setState(() {
                radioItem = val;
              });
            },
          ),
          RadioListTile(
            activeColor: Colors.indigo,
            groupValue: radioItem,
            title: Text('Xyz',style: TextStyle(color: Colors.black54,fontSize:15)),
            value: 'Item 2',
            onChanged: (val) {
              setState(() {
                radioItem = val;
              });
            },
          ),
          RadioListTile(
            activeColor: Colors.indigo,
            groupValue: radioItem,
            title: Text('Pqr',style: TextStyle(color: Colors.black54,fontSize:15)),
            value: 'Item 3',
            onChanged: (val) {
              setState(() {
                radioItem = val;
              });
            },
          ),
          RadioListTile(
            activeColor: Colors.indigo,
            groupValue: radioItem,
            title: Text('Abc',style: TextStyle(color: Colors.black54,fontSize:15)),
            value: 'Item 4',
            onChanged: (val) {
              setState(() {
                radioItem = val;
              });
            },
          ),
        ],
      ),
    );
  }
}