public void PopFront()
{
DLinkedList<int> list = new DLinkedList<int>();
int expectedResult = 1, result;
list.PushFront(1);
list.PushBack(2);
list.PushFront(3);
list.PopFront();
result = list.OnFront();
Assert.AreEqual(expectedResult, result);
}
public void PopFront_ListIsEmptyThrowsException()
{
DLinkedList<int> emptyList = new DLinkedList<int>();
emptyList.PopFront();
}