@Test
public void evaluateShouldReturnAllPatientsThatHaveNeverTakenDrugs() throws Exception {

	List drugs = new ArrayList<Concept>();
	drugs.add(new Drug(3));
	drugs.add(new Drug(2));
	cohortDefinition.setDrugs(drugs);
	cohortDefinition.setWhich(Match.NONE);
	Cohort cohort = Context.getService(CohortDefinitionService.class).evaluate(cohortDefinition, null);
	Assert.assertTrue(cohort.contains(8));
	Assert.assertTrue(cohort.contains(21));
	Assert.assertTrue(cohort.contains(22));
	Assert.assertEquals(3, cohort.size());
}