@Override
    public LockGraphNode getLockGraphNode() {
      return lockGraphNode;
    }

    @Override
    public boolean isAcquiredByCurrentThread() {
      return isHeldByCurrentThread();
    }

    ///// Overridden ReentrantLock methods. /////

    @Override
    public void lock() {
      aboutToAcquire(this);
      try {
        super.lock();
      } finally {