@Test
public void produceNWiseTest() {

    NWiseExtension nWiseExtension = new NWiseExtension();
    Map<String, String[]> variableDomains = new HashMap<>();
    variableDomains.put("A", new String[]{"1", "2", "3", "4"});
    variableDomains.put("B", new String[]{"1", "2", "3", "4"});
    variableDomains.put("C", new String[]{"1", "2", "3", "4"});
    variableDomains.put("D", new String[]{"1", "2", "3", "4"});
    variableDomains.put("E", new String[]{"1", "2", "3", "4"});
    List<Map<String, String>> testCases = nWiseExtension.produceNWise(3,
            new String[]{"A", "B", "C", "D", "E"}, variableDomains);
    Assert.assertEquals(640, testCases.size());
}