@Weak final CycleDetectingReentrantReadWriteLock readWriteLock;

    CycleDetectingReentrantReadLock(CycleDetectingReentrantReadWriteLock readWriteLock) {
      super(readWriteLock);
      this.readWriteLock = readWriteLock;
    }

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