@Test
public void testNullComponentsFails() {

    expectedEx.expect(IllegalArgumentException.class);
    expectedEx.expectMessage("components can't be null");
    HoltWintersPointForecasterParams params = HoltWintersAustouristsTestHelper.buildAustouristsParams(HoltWintersSeasonalityType.MULTIPLICATIVE);
    HoltWintersSimpleTrainingModel subject = new HoltWintersSimpleTrainingModel(params);
    subject.observeAndTrain(0, params, null);
}