static void nativeLF() {
        try {
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
            String osName = System.getProperty("os.name");
            if ((osName != null) && osName.toLowerCase().startsWith("lin")) {
                UIManager.setLookAndFeel("com.sun.java.swing.plaf.gtk.GTKLookAndFeel");
            }
        } catch (Exception E) {
            log.warning("Cannot set native L&F.");
        }
    }