assertTrue(option.startsWith("-D" + Constants.FESS_THUMBNAIL_PATH + "="));
        assertTrue(option.contains(tempDir.getAbsolutePath()));
    }

    // Test offer with valid generator
    public void test_offer_withValidGenerator() {
        TestThumbnailGenerator generator = new TestThumbnailGenerator();
        generator.available = true;
        generator.target = true;