private void doTestDeleteCheckByUserGroup() {
    // UserGroup must be deleted
    UserGroup ug = mgr.find(UserGroup.class, userGroup.getKey());
    Assert.assertNull("UserGroup still available", ug);

    // UserGroupToInvisibleProduct must be deleted
    UserGroupToInvisibleProduct userGroupToInvisibleProduct =
        mgr.find(UserGroupToInvisibleProduct.class, oldUserGroupToInvisibleProduct.getKey());
    Assert.assertNull("UserGroupToInvisibleProduct still available", userGroupToInvisibleProduct);
  }
  private void doTestDeleteCheckByProduct() {
    // Product must be deleted
    Product pu = mgr.find(Product.class, oldproduct.getKey());
    Assert.assertNull("Product still available", pu);

    // UserGroupToInvisibleProduct must be deleted
    UserGroupToInvisibleProduct userGroupToInvisibleProduct =
        mgr.find(UserGroupToInvisibleProduct.class, oldUserGroupToInvisibleProduct.getKey());
    Assert.assertNull("UserGroupToInvisibleProduct still available", userGroupToInvisibleProduct);
  }