Alert when Losting Clipboard owner

import java.awt.Toolkit;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.ClipboardOwner;
import java.awt.datatransfer.StringSelection;
import java.awt.datatransfer.Transferable;

public class Main {
  public static void main(String[] argv) throws Exception {
    ClipboardOwner owner = new MyClipboardOwner();

    StringSelection ss = new StringSelection("A String");
    Toolkit.getDefaultToolkit().getSystemClipboard().setContents(ss, owner);
  }
}

class MyClipboardOwner implements ClipboardOwner {
  public void lostOwnership(Clipboard clipboard, Transferable contents) {
    System.out.println("lost");

  }
}