@Test
  public void valuChangedEventInvokedWhenChangingText() throws Exception {
    panel.setText("foo");
    final MockEventAction action = new MockEventAction();
    panel.getEventHandler().add(ValueChangedEvent.class, action);

    panel.setText("foo");
    assertEquals(false, action.invoked);

    panel.setText("bar");
    assertEquals(true, action.invoked);
  }