private static final ResourceManager INSTANCE = new ResourceManager();

    private final Map<String, ResourceHolder> activeResources = new ConcurrentHashMap<>();
    private final ReferenceQueue<AutoCloseable> referenceQueue = new ReferenceQueue<>();
    private final AtomicLong resourceIdCounter = new AtomicLong();
    private final AtomicLong totalAllocated = new AtomicLong();
    private final AtomicLong totalReleased = new AtomicLong();