public void BulkRepeat()
        {
            StackByLinkedList <int> sl = new StackByLinkedList <int>();

            for (int i = 0; i < 10000; i++)
            {
                sl.Push(i);
            }

            for (int j = 0; j < 1000; j++)
            {
                for (int i = 0; i < 1000; i++)
                {
                    sl.Push(i);
                }

                for (int i = 999; i >= 0; i--)
                {
                    Assert.Equal(i, sl.Pop());
                }
            }

            for (int i = 9999; i >= 0; i--)
            {
                Assert.Equal(i, sl.Pop());
            }
        }
        public void Two()
        {
            StackByLinkedList <int> sl = new StackByLinkedList <int>();

            sl.Push(1);
            sl.Push(2);
            Assert.Equal(2, sl.Pop());
            Assert.False(sl.IsEmpty);
            Assert.Equal(1, sl.Pop());
            Assert.True(sl.IsEmpty);
        }
        public void Five()
        {
            StackByLinkedList <int> sl = new StackByLinkedList <int>();

            sl.Push(1);
            sl.Push(2);
            sl.Push(3);
            sl.Push(4);
            sl.Push(5);
            Assert.Equal(5, sl.Pop());
            Assert.False(sl.IsEmpty);
            Assert.Equal(4, sl.Pop());
            Assert.False(sl.IsEmpty);
            Assert.Equal(3, sl.Pop());
            Assert.False(sl.IsEmpty);
            Assert.Equal(2, sl.Pop());
            Assert.False(sl.IsEmpty);
            Assert.Equal(1, sl.Pop());
            Assert.True(sl.IsEmpty);
        }