SwingXUtilities { public static boolean isUIInstallable(Object property) { return (property == null) || (property instanceof UIResource); } private  SwingXUtilities(); static void updateMnemonicBinding(JComponent c, String pressed); static void updateMnemonicBinding(JComponent c, String pressed, String released); static void setComponentTreeEnabled(Component c, boolean enabled); static void setComponentTreeLocale(Component c, Locale locale); static void setComponentTreeBackground(Component c, Color color); static void setComponentTreeForeground(Component c, Color color); static void setComponentTreeFont(Component c, Font font); static void setHtmlFont(HTMLDocument doc, Font font); static void updateAllComponentTreeUIs(); static void updateAllComponentTreeUIs(Window window); static FutureTask<T> invokeLater(Callable<T> callable); static T invokeAndWait(Callable<T> callable); @SuppressWarnings("unchecked") static T getAncestor(Class<T> clazz, Component c); static boolean isDescendingFrom(Component focusOwner, Component parent); static boolean isUIInstallable(Object property); static void setLeadAnchorWithoutSelection(
            ListSelectionModel selectionModel, int lead, int anchor); static boolean shouldIgnore(MouseEvent mouseEvent,
            JComponent component); static int loc2IndexFileList(JList list, Point point); static void adjustFocus(JComponent component); static int convertModifiersToDropAction(int modifiers,
            int sourcActions);  }
@Test public void testUIInstallable() { assertEquals("null must be uiInstallable ", true, SwingXUtilities.isUIInstallable(null)); assertUIInstallable(new Color(10, 10, 10)); assertUIInstallable(new ColorUIResource(10, 10, 10)); }