@Test
  public final void testDeleteWithPropertiesButParentPreserved() {
    final IExternalDataDAO externalDataDAO = daoFactory.getExternalDataDAO();
    final ExternalDataPE deletedData = findExternalData(CHILD_CODE);

    // Deleted data set should have all collections which prevent it from deletion empty.
    assertTrue(deletedData.getChildren().isEmpty());

    // delete
    externalDataDAO.delete(deletedData);

    // test successful deletion of data set
    assertNull(externalDataDAO.tryGetByTechId(TechId.create(deletedData)));

    // test successful deletion of data set properties
    assertFalse(deletedData.getProperties().isEmpty());
    List<EntityTypePropertyTypePE> retrievedPropertyTypes =
        daoFactory
            .getEntityPropertyTypeDAO(EntityKind.DATA_SET)
            .listEntityPropertyTypes(deletedData.getEntityType());
    for (DataSetPropertyPE property : deletedData.getProperties()) {
      int index = retrievedPropertyTypes.indexOf(property.getEntityTypePropertyType());
      EntityTypePropertyTypePE retrievedPropertyType = retrievedPropertyTypes.get(index);
      assertFalse(retrievedPropertyType.getPropertyValues().contains(property));
    }

    // deleted sample had parent connected that should not have been deleted
    // NOTE: somehow cannot get parents even though connection is the same as with children
    // DataPE parent = deletedData.tryGetParent();
    // assertNotNull(parent);
    // assertNotNull(externalDataDAO.tryGetByTechId(new TechId(HibernateUtils.getId(parent))));
    findExternalData(PARENT_CODE);
  }
  @Test(expectedExceptions = DataIntegrityViolationException.class)
  public final void testDeleteFailWithChildrenDatasets() {
    final IExternalDataDAO externalDataDAO = daoFactory.getExternalDataDAO();
    final ExternalDataPE deletedData = findExternalData(PARENT_CODE);

    // Deleted data set should have 'child' data sets which prevent it from deletion.
    assertFalse(deletedData.getChildren().isEmpty());

    // delete
    externalDataDAO.delete(deletedData);
  }