Develop a program to demonstrate the use of JTree i Swing Java Programming

import javax.swing.*; 
import javax.swing.tree.DefaultMutableTreeNode; 
public class Tree { 
 
Tree(){ 
    JFrame f=new JFrame(); 
    DefaultMutableTreeNode s=new DefaultMutableTreeNode("India"); 
    DefaultMutableTreeNode s2=new DefaultMutableTreeNode("Maharashtra"); 
    DefaultMutableTreeNode s3=new DefaultMutableTreeNode("Gujrath"); 
    s.add(s2); 
    s.add(s3); 
    DefaultMutableTreeNode s4=new DefaultMutableTreeNode("Mumbai"); 
    DefaultMutableTreeNode s5=new DefaultMutableTreeNode("Pune"); 
    DefaultMutableTreeNode s6=new DefaultMutableTreeNode("Nashik"); 
    DefaultMutableTreeNode s7=new DefaultMutableTreeNode("Nagpur"); 
    s2.add(s4);
s2.add(s5);
s2.add(s6);
s2.add(s7);     
    JTree j=new JTree(s); 
    f.add(j); 
    f.setSize(200,200); 
    f.setVisible(true); 
} 
public static void main(String[] args) { 
    new Tree(); 
}}
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