Canguro.Model.Undo.AddDelListAction.Undo C# (CSharp) Метод

        public void Undo()
        {
            if (isAdd)
            {
                if (collection is IDictionary)
                {
                    obj = ((IDictionary)collection)[key];
                    ((IDictionary)collection).Remove(key);
                }
                else if (collection is IList)
                {
                    obj = ((IList)collection)[(int)key];
                    ((IList)collection).RemoveAt((int)key);
                }
            }
            else
            {
                if (collection is IDictionary)
                {
                    ((IDictionary)collection).Add(key, obj);
                    obj = null;
                }
                else if (collection is IList)
                {
                    ((IList)collection).Insert((int)key, obj);
                    obj = null;
                }
            }
            isAdd = !isAdd;
        }