public static void Main()
        {
            Console.WriteLine("Creating first one with new...");
            SumOf app = new SumOf(1, 10);

            Console.WriteLine("Creating second one with deserialize...");
            SumOf newInstance = SumOf.DeSerialize();

            newInstance.DisplaySums();
        }
        public static SumOf DeSerialize()
        {
            FileStream fileStream =
                new FileStream("DoSum.out", FileMode.Open);
            BinaryFormatter binaryFormatter =
                new BinaryFormatter();
            SumOf retVal = ( SumOf )binaryFormatter.Deserialize(fileStream);

            fileStream.Close();
            return(retVal);
        }