@Test
  public void testUpdate() {

    ds.begin(ReadWrite.WRITE);
    try {
      Ontology ont = Ontology.loadOntology(ds, testOntologyName);

      JSONObject values = new JSONObject();

      OntologyInstance instance = ont.createInstance(simpleClassId, values);

      JSONObject rep = instance.getJSONRepresentation();

      assertTrue(rep.length() == 0);

      // Add DataProperty

      values.put(idChar + dataPropId, new JSONArray("[test]"));

      instance.update(values);

      rep = instance.getJSONRepresentation();

      assertTrue(rep.length() == 1);
      assertTrue(rep.toString().equals(values.toString()));

      ds.commit();
    } catch (JSONException e) {
      ds.abort();
      fail(e.getMessage());
    } finally {
      ds.end();
    }
  }