@Test
public void getAllClassesTest() throws Exception {

    // Setup:
    Set<String> expectedClasses = Stream.of("http://test.com/ontology1#TestClassA",
            "http://test.com/ontology1#TestClassB", "http://test.com/ontology1#TestClassC",
            "http://test.com/ontology1#TestClassD", "http://test.com/ontology1#TestClassE").collect(Collectors.toSet());
    Set<OClass> classes = ontology.getAllClasses();
    assertEquals(expectedClasses.size(), classes.size());
    classes.stream()
            .map(oClass -> oClass.getIRI().stringValue())
            .forEach(iri -> assertTrue(expectedClasses.contains(iri)));
}