PurgeThumbnailJob job = new PurgeThumbnailJob();
        assertNotNull(job);
        assertEquals(30L * 24 * 60 * 60 * 1000L, job.getExpiry());
    }

    // Test getExpiry with default value
    public void test_getExpiry_default() {
        assertEquals(30L * 24 * 60 * 60 * 1000L, purgeThumbnailJob.getExpiry());
    }

    // Test expiry setter with valid value
    public void test_expiry_validValue() {

     */
    public String execute() {
        try {
            final long count = ComponentUtil.getThumbnailManager().purge(getExpiry());
            return "Deleted " + count + " thumbnail files.";
        } catch (final Exception e) {
            logger.error("Failed to purge thumbnails.", e);
            return e.getMessage();
        }
    }