    @Test
    public void whenGetLatestThenReturnNetwork() {

        TestObserver<String> testObserver = TestObserver.create();
        when(networkDataSource.getAndUpdate(parameter, cacheDataSource)).thenReturn(Maybe.just(NETWORK_DATA));

        sut.getLatest(parameter)
                .subscribe(testObserver);

        testObserver.assertResult(NETWORK_STRING); // includes .assertComplete().assertNoErrors()
        verify(networkDataSource).getAndUpdate(parameter, cacheDataSource);
        verifyZeroInteractions(cacheDataSource);
    }