@Test
public void getOnStopHandlers() {

    final OnStopHandler onStopHandler = mock(OnStopHandler.class);
    sut.onStop(onStopHandler);
    final List<OnStopHandler> onStopHandlers = sut.getOnStopHandlers();
    assertThat(onStopHandlers).hasSize(1);
    assertThat(onStopHandlers).contains(onStopHandler);
}