class ThreadSafeSingletonWithDoubleCheckedLocking {
  private static ThreadSafeSingletonWithDoubleCheckedLocking threadSafeSingleton;
  /**
  * private constructor so that other classes can't
  * instantiate it through constructor
  * any instantiation while creating new singleton instance should come here
  */

  private ThreadSafeSingletonWithDoubleLocking() {}

  public static synchronized ThreadSafeSingletonWithDoubleCheckedLocking getInstance() {
    if(threadSafeSingleton == null) {
       synchronized(ThreadSafeSingletonWithDoubleCheckedLocking.class) {
           threadSafeSingleton = new ThreadSafeSingletonWithDoubleCheckedLocking();
       }
    }
    return threadSafeSingleton;
  }
}