@Test public void testSubscriptionWhenExecutingUseCase() {

	// 如果不给他一个Scheduler的话, 会抛nullpoint异常， 所以Assert.assertThat(testSubscriber.isUnsubscribed(), is
     // (true)); 在抛出异常时，会默认解除testSubscriber的订阅
	TestSubscriber<Integer> testSubscriber = new TestSubscriber<>();
	//        given(mockPostExecutionThread.getScheduler()).willReturn(new TestScheduler());
	useCase.execute(testSubscriber);
	// ----------------------------------------------------------------------------
	Mockito.when(!testSubscriber.isUnsubscribed())
				 .thenThrow(new NullPointerException("scheduler must be not null"));
}