public static void DetectMediaType(MediaTypeBase item)
        {
            string type = "";

            if (item == null)
            {
                return;
            }

            if (item is Movie)
            {
                type = "Movie";
            }
            if (item is Book)
            {
                type = "Book";
            }
            if (item is Album)
            {
                type = "Album";
            }

            if (type == "")
            {
                throw new System.ArgumentException("Unexpected media subtype encountered.", "type");
            }

            Console.WriteLine(item.Title + " is " + type);
        }
        public static void Display(MediaTypeBase item)
        {
            if (item == null)
            {
                return;
            }

            if (item is Movie)
            {
                Console.WriteLine(((Movie)item).GetDisplayText());
            }
            else if (item is Book)
            {
                Console.WriteLine(((Book)item).GetDisplayText());
            }
            else if (item is Album)
            {
                Console.WriteLine(((Album)item).GetDisplayText());
            }
            else
            {
                throw new System.ArgumentException("Unexpected media subtype encountered.", "type");
            }
        }