Product oldProduct = TestUtil.createProduct("fake id", "fake name");
Content content = new Content("foobar", null, null, null, null, null, null, null);
Content content2 = new Content("baz", null, null, null, null, null, null, null);
oldProduct.addContent(content);
newProduct.addContent(content2);
Set<Product> products = new HashSet<Product>();
products.add(newProduct);