try {
        super.lock();
      } finally {
        lockStateChanged(this);
      }
    }

    @Override
    public void lockInterruptibly() throws InterruptedException {
      aboutToAcquire(this);
      try {
        super.lockInterruptibly();
      } finally {
        lockStateChanged(this);
      }
    }

    @Override
    public boolean tryLock() {