### Question:
LienzoCanvasNotification { @PreDestroy public void destroy() { if (null != outHandler) { outHandler.removeHandler(); outHandler = null; } panel = null; } @Inject  LienzoCanvasNotification(final View view); void init(final Supplier<LienzoPanel> panel); void show(final String text); void hide(); @PreDestroy void destroy();  }### Answer:
@Test public void testDestroy() { HandlerRegistration r = mock(HandlerRegistration.class); tested.outHandler = r; tested.destroy(); verify(r, times(1)).removeHandler(); assertNull(tested.outHandler); assertNull(tested.panel); }