cause a deadlock.java

public class ThreadNinja {
  private int rank;

  public synchronized void fight(ThreadNinja enemy) {
    if (!enemy.canDefend(this)) {
      rank++;
    }   
  }

  public synchronized boolean canDefend(ThreadNinja enemy) {
    if (this.rank > enemy.rank) {
      this.rank++;
      return true;
    }   
    return false;
  }

  public static void main(String[] args) {
    // write code here that will cause a deadlock in the methods above.
  }
}