@Test
public void invalidParametersDatasetIdNoOperations() {

    // given parameters with a dataset id
    AggregationParameters parameters = new AggregationParameters();
    parameters.setDatasetId("dataset#7568");
    // when
    Set<ConstraintViolation<AggregationParameters>> constraintViolations = validator.validate(parameters);
    // then 2 violations (operations and groupBy are empty)
    Assert.assertEquals(2, constraintViolations.size());
}