if (toolkit instanceof ClasspathToolkit) ((ClasspathToolkit)toolkit).registerImageIOSpis(this);
  private IIORegistry()  {    super(defaultCategories.iterator());    // XXX: Register built-in Spis here.    Toolkit toolkit = Toolkit.getDefaultToolkit();    if (toolkit instanceof ClasspathToolkit)      ((ClasspathToolkit)toolkit).registerImageIOSpis(this);        registerApplicationClasspathSpis();  }