public void List_IndexOf_WithInvalidItem_DoesNotFindItem()
            {
                var source = new List <int> {
                    13
                };
                var list   = new ReadWriteList <int>(source);
                int result = list.IndexOf(17);

                Assert.AreEqual(-1, result, "Item should not be found.");
            }
            public void List_IndexOf_WithValidItem_FindsItem()
            {
                var source = new List <int> {
                    13
                };
                var list   = new ReadWriteList <int>(source);
                int result = list.IndexOf(13);

                Assert.AreEqual(0, result, "Item should be found.");
            }