ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
        File outputFile = File.createTempFile("generator_", ".png");

        String imagePath = "thumbnail/600x400.png";
        try (ImageInputStream input = ImageIO.createImageInputStream(classLoader.getResourceAsStream(imagePath))) {
            generator.saveImage(input, outputFile);
        }

            }
        });
    }

    protected String getImageMimeType(final File imageFile) {
        final String path = imageFile.getAbsolutePath();
        if (path.endsWith(".png")) {
            return "image/png";
        }
        if (path.endsWith(".gif")) {
            return "image/gif";
        }
        if (path.endsWith(".jpg") || path.endsWith(".jpeg")) {
            return "image/jpeg";
        }

        final String mimeType = responseData.getMimeType();
        if (mimeType == null) {
            return true;
        }

        return switch (mimeType) {
        case "image/png", "image/gif", "image/jpeg", "image/bmp" -> true;
        default -> false;
        };
    }

    protected Result saveImage(final ImageInputStream input, final File outputFile) throws IOException {

     * audio/mp4=mp4a<br>
     * audio/ogg=oga<br>
     * audio/x-wav=wav<br>
     * image/webp=webp<br>
     * image/bmp=bmp<br>
     * image/x-icon=ico<br>
     * image/x-icon=ico<br>
     * image/png=png<br>
     * image/svg+xml=svg<br>
     * image/tiff=tiff<br>
     * image/jpeg=jpg<br>
     *  */
    String INDEX_FILETYPE = "index.filetype";

    /** The key of the configuration. e.g. 100 */

            });
            task.from(extension.getCssFiles(), sub -> sub.into("css"));
            task.from(extension.getUserManual().getRoot().dir("img"), sub -> {
                sub.include("**/*.png", "**/*.gif", "**/*.jpg", "**/*.svg");
                sub.into("img");
            });
            task.from(extension.getUserManual().getResources());

            task.from(generateDocinfo);

    private volatile boolean generating;

    private Thread thumbnailQueueThread;

    protected int thumbnailPathCacheSize = 10;

    protected String imageExtention = "png";

    protected int splitSize = 10;

    protected int thumbnailTaskQueueSize = 10000;

    protected int thumbnailTaskBulkSize = 100;

    protected long thumbnailTaskQueueTimeout = 10 * 1000L;

  public static final MediaType ICO = createConstant(IMAGE_TYPE, "vnd.microsoft.icon");
  public static final MediaType JPEG = createConstant(IMAGE_TYPE, "jpeg");
  public static final MediaType PNG = createConstant(IMAGE_TYPE, "png");

  /**
   * The Photoshop File Format ({@code psd} files) as defined by <a
   * href="http://www.iana.org/assignments/media-types/image/vnd.adobe.photoshop">IANA</a>, and

    /** The key of the message: ICO Image */
    public static final String LABELS_facet_filetype_ico = "{labels.facet_filetype_ico}";

    /** The key of the message: PNG Image */
    public static final String LABELS_facet_filetype_png = "{labels.facet_filetype_png}";

    /** The key of the message: SVG Image */
    public static final String LABELS_facet_filetype_svg = "{labels.facet_filetype_svg}";