@Test
public void evaluateShouldReturnAllPatientsCurrentlyActiveOnDrugsFromDate() throws Exception { 

	cohortDefinition.setActiveOnOrAfter(DateUtil.getDateTime(2013, 12, 7));
	Cohort cohort = Context.getService(CohortDefinitionService.class).evaluate(cohortDefinition, null);
	Assert.assertTrue(cohort.contains(22));
	Assert.assertTrue(cohort.contains(7));
	Assert.assertTrue(cohort.contains(2));
	Assert.assertTrue(cohort.contains(21));
	Assert.assertEquals(4, cohort.size());
}