public void TestLoopDetection()
{
// Arrange
// null head
SLLNode nullHead = null;
// single node
SLLNode singleNode = new SLLNode(1);
// common case
SLLNode commonCaseHead = new SLLNode(1);
SLLNode second = new SLLNode(2);
commonCaseHead.Next = second;
SLLNode third = new SLLNode(3);
second.Next = third;
SLLNode fourth = new SLLNode(4);
third.Next = fourth;
SLLNode fifth = new SLLNode(5);
fourth.Next = fifth;
SLLNode sixth = new SLLNode(6);
fifth.Next = sixth;
sixth.Next = third;
// Act
SLLNode nullHeadResult = LinkedLists.LoopDetection(nullHead);
SLLNode singleNodeResult = LinkedLists.LoopDetection(singleNode);
SLLNode commonCaseResult = LinkedLists.LoopDetection(commonCaseHead);
// Assert
Assert.IsNull(nullHeadResult);
Assert.IsNull(singleNodeResult);
Assert.AreEqual(third, commonCaseResult);
}