flutter how to show stateful widget from another code example

Example 1: make stateful widget flutter

class MyClass extends StatefulWidget {
	@override
    MyClassState createState() => new MyClassState();
}

class MyClassState extends State {
	//Widgets and other code here
}

Example 2: stateless widget flutter

class GreenFrog extends StatelessWidget {
  const GreenFrog({ Key key }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(color: const Color(0xFF2DBD3A));
  }
}