public void Test_Add_SingleTeacher_ReturnsThatTeacher()
        {
            CalculateCurrentStudentsAmount sc = new CalculateCurrentStudentsAmount();

            int result = sc.Add("1");

            NUnit.Framework.Assert.AreEqual(1, result);
        }
        public void TestAddStudent()
        {
            CalculateCurrentStudentsAmount sc = new CalculateCurrentStudentsAmount();

            int result = sc.Add("");

            NUnit.Framework.Assert.That(result, Is.EqualTo(0));
        }