public void TestFindAllCategories()
        {
            //prepare
            SubjectModel dut = new SubjectModel(crud);

            //test
            List <Category> result = dut.FindAllCategories();

            //validate
            Assert.IsNotNull(result);
            Assert.AreEqual(10, result.Count());        /* JH: VERY DEPENDENT ON THE CURRENT STATE OF THE DATABASE, DO NOT TEST FOR THIS */
            Assert.AreEqual("Varkens", result[4].Name); /* JH: VERY DEPENDENT ON THE CURRENT STATE OF THE DATABASE, DO NOT TEST FOR THIS */
            /* JH: You could test if Assert.IsTrue(result.Contains(x => x.Name == "Varkens"), "Varkens present"); */
        }