/** Tests whether the observer is correctly notified on the event dispatch thread. */
 @Test
 public void testPerformGUIUpdate() {
   final Throwable err = new RuntimeException();
   observer.commandCompletedUI(RESULT, err);
   EasyMock.replay(observer);
   ObservableCommandTestImpl cmd =
       new ObservableCommandTestImpl(init, observer) {
         @Override
         String getResult() {
           return RESULT;
         }
       };
   cmd.setException(err);
   cmd.performGUIUpdate();
   EasyMock.verify(observer);
 }