String result = purgeThumbnailJob.execute();

        assertTrue(result.contains("Test exception"));
    }

    // Test execute with large number of deleted files
    @Test
    public void test_execute_largeNumberOfFiles() {
        thumbnailManager.setPurgeCallCount(Long.MAX_VALUE);

        String result = purgeThumbnailJob.execute();

        assertEquals("Deleted " + Long.MAX_VALUE + " thumbnail files.", result);