public void AddFirst_CheckHead_CheckTail_CheckCount() { // Act linkedList.AddNodeInFirst(5); linkedList.AddNodeInFirst(4); linkedList.AddNodeInFirst(3); // 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); }