public void AddLast_CheckHead_CheckTail_CheckCount()
        {
            // Act
            linkedList.AddNodeInLast(3);
            linkedList.AddNodeInLast(4);
            linkedList.AddNodeInLast(5);

            // Assert
            Assert.Equal(tailExpected, linkedList.Tail);
            Assert.Equal(headExpected, linkedList.Head);
            Assert.Equal(middleExpected, linkedList.Head.Next);
            Assert.Equal(middleExpected, linkedList.Tail.Previous);
            Assert.Equal(3, linkedList.Count);
        }