@Test
public void testIssue144() throws Exception {

  UIManager.put("Addon.title", "customized");
  UIManager.put("Addon.border", new LineBorder(Color.blue));
  
  Addon addon = new Addon();
  LookAndFeelAddons.contribute(addon);
  
  assertEquals("customized", UIManager.get("Addon.title"));
  assertEquals("my subtitle", UIManager.get("Addon.subtitle"));
  assertTrue(UIManager.get("Addon.border") instanceof LineBorder);
  
  UIManager.put("Addon.title", null);
  assertEquals("my title", UIManager.get("Addon.title"));
}