@Test
public void getCurrentUSDPrice_oneNext() throws ParseException {

    Date date = newDate(1);
    float rate = 2.3456f;
    BPIService service = mock(BPIService.class);
    when(service.currentPrice()).thenReturn(Observable.from(new PriceDto[]{
            newUSDPrice(date, rate)
    }));
    BPIServiceClient client = new BPIServiceClient(service);
    TestSubscriber<BPI> subscriber = new TestSubscriber<>();
    client.getCurrentUSDPrice().subscribe(subscriber);
    List<BPI> expectedResults = Lists.newArrayList(
            new BPI(date, rate)
    );
    subscriber.assertReceivedOnNext(expectedResults);
    subscriber.assertTerminalEvent();
    subscriber.assertNoErrors();
}