public static void Demo()
        {
            var example = new ListDemo();

            // Without using Null Coalescing Assignment
            //if (example.LuckyNumbers == null)
            //{
            //    example.LuckyNumbers = new List<int>();
            //}

            // we can use Not Null check but it will not do anything if its null
            //example?.LuckyNumbers?.Add(16);

            // With using Null Coalescing Assignment. If its null will instantiate
            // a new List<int>
            example.LuckyNumbers ??= new List <int>();


            example.LuckyNumbers.Add(15);

            foreach (var item in example.LuckyNumbers)
            {
                Console.WriteLine($"Lucky Number: { item }");
            }
        }
        public static void Demo()
        {
            var example = new ListDemo();

            //if (example.LuckyNumbers == null) example.LuckyNumbers = new List<int>();

            example.LuckyNumbers ??= new List <int>();

            example.LuckyNumbers.Add(15);

            foreach (var item in example.LuckyNumbers)
            {
                Console.WriteLine($"Lucky Number: { item }");
            }
        }