code for varience in generic types in C#

class Program
    {
        public class VarianceWork
        {
            public static void AddItem<I, L>(List<I> item, List<L> list)
                where I : L
            {
                foreach (I newItem in item)
                {
                    list.Add(newItem);
                    Console.WriteLine("Added");
                }
            }
        }

        static void Main()
        {
            List<int> li = new List<int>();
            li.Add(1);
            li.Add(2);
            List<object> obj = new List<object>();

            VarianceWork.AddItem<int, object>(li, obj);
        }
    }