@Test
public void simpleDisjunctionOfConjunctions() {

    Set<String> dnf = createDisjunctiveNormalForm(createSimpleDisjunctionOfConjunctionsQuery());
    assertEquals(2, dnf.size());
    assertTrue(dnf.contains("c1=v1 AND c2=v2"));
    assertTrue(dnf.contains("c3=v3 AND c4=v4"));
}