void TraverseLinkedList()
        {
            SimpleLinkedListNode node = head;

            while (node != null)
            {
                Console.Write(node._data + " ");
                node = node._next;
            }
        }
        public SimpleLinkedList()
        {
            SimpleLinkedList first = new SimpleLinkedList();

            first.head = new SimpleLinkedListNode(1);
            SimpleLinkedListNode second = new SimpleLinkedListNode(2);
            SimpleLinkedListNode third  = new SimpleLinkedListNode(3);

            first.head._next = second;
            second._next     = third;

            first.TraverseLinkedList();
        }
 public SimpleLinkedListNode(int data)
 {
     _data = data;
     _next = null;
 }