public void VerifyPeekInStack()
        {
            var actual = new StackUsingArray(3);

            actual.Push(12);
            actual.Push(14);
            actual.Push(16);

            Assert.AreEqual(3, actual.Count());

            var value = actual.Peek();

            Assert.AreEqual(16, value);
            Assert.AreEqual(3, actual.Count());
        }
        public void VerifyPushInStack()
        {
            var actual = new StackUsingArray(3);

            actual.Push(12);
            actual.Push(14);
            actual.Push(16);

            Assert.AreEqual(3, actual.Count());
        }