1. import java.io.*;2. public class Forest implements Serializable {3.   private Tree tree = new Tree();4.   public static void main(String [] args) {5.    Forest f = new Forest();6.    try {7.     FileOutputStream fs = new FileOutputStream("Forest.ser");8.     ObjectOutputStream os = new ObjectOutputStream(fs);9.     os.writeObject(f); os.close();10.    } catch (Exception ex) { ex.printStackTrace(); }11.   } 12.}13. class Tree { }