@Test
public void getCommentsTest() {

    List<List<Comment>> comments = manager.getComments(request1.getResource());
    assertEquals(3, comments.size());
    String firstThreadTime = comments.get(0).get(0).getProperty(VALUE_FACTORY.createIRI(_Thing.issued_IRI)).get().stringValue();
    String secondThreadTime = comments.get(1).get(0).getProperty(VALUE_FACTORY.createIRI(_Thing.issued_IRI)).get().stringValue();
    assertTrue(OffsetDateTime.parse(firstThreadTime).isBefore(OffsetDateTime.parse(secondThreadTime)));
}