How To Change Button Text Dynamically In Flutter App

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
        home: Scaffold(
            appBar: AppBar(
              centerTitle: true,
                backgroundColor: Colors.deepPurple,
                title: Text('Change Button Above Text Dynamically')
            ),
            body: Center(
                child: CustomButton()
            )
        )
    );
  }
}

class CustomButton extends StatefulWidget {
  CustomButtonState createState() => CustomButtonState();
}

class CustomButtonState extends State<CustomButton> {
  String buttonText = 'Old Text';
  updateButtonText(){
    setState(() {
      buttonText = 'New Text';
    });
  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              RaisedButton(
                onPressed: ()=> print('Clicked'),
                color: Colors.orange,
                textColor: Colors.white,
                padding: EdgeInsets.fromLTRB(10, 10, 10, 10),
                child: Text('$buttonText'),
              ),
              RaisedButton(
                onPressed: updateButtonText,
                color: Colors.deepPurple,
                textColor: Colors.white,
                padding: EdgeInsets.fromLTRB(10, 10, 10, 10),
                child: Text('Change Button Above Text'),
              ),

            ],
          ),
        ));
  }
}