private static void AbstractNormalVirtualMethods()
        {
            SoftwareDeveloper sd = new SoftwareDeveloper("SoftwareDeveloper1");
            Employee          e  = (Employee)sd;    //same instance as above

            //Normal method
            Console.Write("\n###Hide");
            sd.PrintWageNormal();
            e.PrintWageNormal();

            //Virtual method
            Console.Write("\n###Override");
            sd.PrintWageVirtual();
            e.PrintWageVirtual();

            //Abstract method
            Console.WriteLine("\n###Abstract");
            sd.PrintWageAbstract();
            e.PrintWageAbstract();
        }