DocMap docMap = new DocMap(parentMap);

        assertTrue(docMap.isEmpty());
        assertEquals(0, docMap.size());

        docMap.put("key1", "value1");
        assertFalse(docMap.isEmpty());
        assertEquals(1, docMap.size());

        docMap.put("key2", "value2");
        assertFalse(docMap.isEmpty());
        assertEquals(2, docMap.size());

        docMap.clear();

        assertEquals(sitePath, viewHelper.getSitePath(docMap));

        urlLink = "www.google.com";
        sitePath = "www.google.com";
        docMap.put(fieldName, urlLink);
        assertEquals(sitePath, viewHelper.getSitePath(docMap));

        urlLink = "smb://123.45.678.91/share1";
        sitePath = "123.45.678.91/share1";
        docMap.put(fieldName, urlLink);

        Map<String, Object> docMap = new HashMap<>();
        docMap.put("mimetype", "application/pdf");
        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");

        thumbnailManager.add(generator);

        Map<String, Object> docMap = new HashMap<>();
        docMap.put("_id", "docid1");
        docMap.put("url", "http://example.com");

        boolean result = thumbnailManager.offer(docMap);
        assertTrue(result);
    }

    // Test offer with no matching generator
    @Test

        }
        return false;
    }

    /**
     * Gets the image filename for a document based on its document map.
     *
     * @param docMap the document data map
     * @return the generated image filename
     */
    protected String getImageFilename(final Map<String, Object> docMap) {

        // when proper conditions are not met.

        Map<String, Object> docMap = new HashMap<>();

        // This will return false because getFessConfig() will fail
        // We verify the method handles the case gracefully
        try {
            emptyGenerator.isTarget(docMap);
        } catch (IllegalStateException e) {
            // Expected when container is not initialized

     *
     * @param path the file path or URL of the document
     * @param docMap the document metadata map containing field values
     * @return a tuple containing the generator name, thumbnail ID, and path
     */
    @Override
    public Tuple3<String, String, String> createTask(final String path, final Map<String, Object> docMap) {
        final FessConfig fessConfig = ComponentUtil.getFessConfig();

        generator = new TestThumbnailGenerator();
        Map<String, Object> docMap = new HashMap<>();
        docMap.put("id", "doc123");

        // Since createTask depends on FessConfig, it may not work properly
        // in unit tests without full container
        try {
            generator.createTask("/path/to/thumb.jpg", docMap);
        } catch (Exception e) {
            // Expected when FessConfig is not available

            if (source != null) {
                final Map<String, Object> docMap = new HashMap<>(source);
                docMap.put(fessConfig.getIndexFieldId(), hit.getId());
                docMap.put(fessConfig.getIndexFieldVersion(), hit.getVersion());
                docMap.put(fessConfig.getIndexFieldSeqNo(), hit.getSeqNo());
                docMap.put(fessConfig.getIndexFieldPrimaryTerm(), hit.getPrimaryTerm());

    }

    @Test
    public void test_calculateDocumentSize_withNullValue() {
        final Map<String, Object> docMap = new HashMap<>();
        docMap.put("id", "test");
        docMap.put("nullField", null);

        long size = indexingHelper.calculateDocumentSize(docMap);
        assertTrue(size > 0);
    }