@Test
public void testSingleDelivery() {

    Observer observer = mock(Observer.class);
    mMediator.addSource(mSource, observer);
    mSource.setValue("flatfoot");
    verify(observer).onChanged("flatfoot");
    mRegistry.handleLifecycleEvent(Lifecycle.Event.ON_STOP);
    reset(observer);
    verify(observer, never()).onChanged(any());
}