ThumbnailManager mockThumbnailManager = new ThumbnailManager() {
            @Override
            public int generate(ExecutorService executorService, boolean cleanup) {
                counter.incrementAndGet();
                // Return 0 to exit the loop
                return 0;
            }
        };
        ComponentUtil.register(mockThumbnailManager, "thumbnailManager");
    }

    private PurgeThumbnailJob purgeThumbnailJob;
    private MockThumbnailManager thumbnailManager;

    @Override
    public void setUp() throws Exception {
        super.setUp();
        purgeThumbnailJob = new PurgeThumbnailJob();

        // Create a mock ThumbnailManager
        thumbnailManager = new MockThumbnailManager();

        ComponentUtil.register(thumbnailManager, "thumbnailManager");
    }