public static void loadLookAndFeel() throws ClassNotFoundException {
        LookAndFeel laf = UIManager.getLookAndFeel();
        if (laf == null) {
            return; // never null
        }
        ClassLoader cl = laf.getClass().getClassLoader();
        if (cl == null) {
            return; // null for system class loader (?)
        }
        
        // Does not work: cl.getClass().equals(JarClassLoader.class)
        if (cl.getClass().getName().equals(JarClassLoader.class.getName())) {
            UIDefaults uidef = UIManager.getDefaults();
            Enumeration<?> en = uidef.keys();
            while (en.hasMoreElements()) {
                String sClass = (String)en.nextElement();
                if (sClass.endsWith("UI")) {
                    Object obj = uidef.get(sClass);
                    // If the obj is java.lang.String load the class,
                    // otherwise it's already loaded java.lang.Class
                    if (obj instanceof String) {
                        Class<?> clazz = cl.loadClass((String)obj);
                        uidef.put(clazz.getName(), clazz);
                    }
                }
            }
        }
    } // loadLookAndFeel()