5. public class Lockdown implements Runnable {6. public static void main(String[] args) {7. new Thread(new Lockdown())start();8. new Thread(new Lockdown())start();9. }10. public void run() { locked(Thread.currentThread()getId()); }11. synchronized void locked(long id) {12. System.out.print(id + "a ");13. System.out.print(id + "b ");14. }15. }