@Test
    public void test_isTarget() {
        // Test isTarget method
        generator = new TestThumbnailGenerator();
        Map<String, Object> docMap = new HashMap<>();

        // Note: isTarget requires FessConfig which needs container
        // We can only verify the method handles missing container gracefully
        try {
            generator.isTarget(docMap);
        } catch (IllegalStateException e) {

        assertTrue(emptyGenerator.isAvailable());
    }

    @Test
    public void test_isTarget() {
        // Initialize without container
        emptyGenerator = new EmptyGenerator();

        // Note: isTarget method requires FessConfig from ComponentUtil
        // which needs container initialization.
        // We can only test that the method can be called without crashing
        // when proper conditions are not met.

        assertTrue(thumbnailGenerator.isTarget(docMap));
    }

    @Test
    public void test_isTarget_withUnsupportedMimeType() {
        // Test with unsupported document type
        Map<String, Object> docMap = new HashMap<>();
        docMap.put("mimetype", "application/unknown");
        assertFalse(thumbnailGenerator.isTarget(docMap));
    }

    @Test

            return generateResult;
        }

        @Override
        public boolean isAvailable() {
            return available;
        }

        @Override
        public boolean isTarget(Map<String, Object> docMap) {
            return target;
        }

        @Override
        public Tuple3<String, String, String> createTask(String path, Map<String, Object> docMap) {
            return task;

        assertTrue(rule.isTarget(12, 30, 5)); // 12:30 on Thursday

        // Within time range but not matching day
        assertFalse(rule.isTarget(12, 30, 2)); // 12:30 on Monday
        assertFalse(rule.isTarget(12, 30, 4)); // 12:30 on Wednesday
        assertFalse(rule.isTarget(12, 30, 6)); // 12:30 on Friday
        assertFalse(rule.isTarget(12, 30, 7)); // 12:30 on Saturday
    }

     */
    public boolean offer(final Map<String, Object> docMap) {
        for (final ThumbnailGenerator generator : generatorList) {
            if (generator.isTarget(docMap)) {
                final String path = getImageFilename(docMap);
                final Tuple3<String, String, String> task = generator.createTask(path, docMap);
                if (task != null) {