class ToolboxAvailable {

    /**
     * Checks if the toolbox if available. If it is, the toolbox is started. If it isn't, an error message is shown.
     *
     * @param args the command-line args
     */
    public static void main(String[] args) {<FILL_FUNCTION_BODY>}
}

        if (GraphicsEnvironment.isHeadless()) {
            System.out.println(Document.getVersion() + " Toolbox error: headless display");
        } else {
            try {
                Toolbox.main(args);
            } catch (Exception e) {
                JOptionPane.showMessageDialog(null,
                        "You need the iText-toolbox.jar with class com.lowagie.toolbox.Toolbox to use the iText Toolbox.",
                        Document.getVersion() + " Toolbox error",
                        JOptionPane.ERROR_MESSAGE);
            }
        }
    
<no_super_class>