public void Test_DequeueFirst()
{
MyDeque <int> deq = new MyDeque <int>();
deq.EnqueueLast(1);
deq.EnqueueLast(2);
deq.EnqueueLast(3);
deq.EnqueueLast(4);
int expected = deq.PeekFirst();
int count1 = deq.Count;
int actual = deq.DequeueFirst();
int count2 = deq.Count;
Assert.AreEqual(actual, expected);
Assert.AreNotEqual(count1, count2);
}