@Test
public void testUpdate() {

    final RevisionInfo revisionInfo = new RevisionInfo(null, 0L);
    final TestEntity requestEntity = new TestEntity("1", revisionInfo);
    final RevisableEntity createdEntity = entityService.create(
            requestEntity, "user1", () -> requestEntity);
    assertNotNull(createdEntity);
    assertEquals(requestEntity.getIdentifier(), createdEntity.getIdentifier());
    assertNotNull(createdEntity.getRevision());
    assertEquals(1, createdEntity.getRevision().getVersion().longValue());
    final RevisableEntity updatedEntity = entityService.update(
            createdEntity, "user2", () -> createdEntity);
    assertNotNull(updatedEntity.getRevision());
    assertEquals(2, updatedEntity.getRevision().getVersion().longValue());
    assertEquals("user2", updatedEntity.getRevision().getLastModifier());
}