import javax.swing.* ;

class FirstFrame extends JFrame {
    public FirstFrame() {
        setTitle("FirstFrame") ;
        setSize(450, 300) ;
    }
}

public class FrameTest {
    public static void main(String [] args) {
        JFrame frame = new FirstFrame() ;

        frame.show() ;

        System.out.println("main() done.") ;
    }
}