public void deleteDuplicates() {
      if (_root == null || _root.Next == null) {
         return;
      }

      Node<T> current = _root;

      while (current != null) {
         Node<T> runner = current;

         while (runner.Next != null) {
            if (runner.Next.Data == current.Data) {
               runner.Next = runner.Next.Next;
            } else {
               runner = runner.Next;
            }
         }

         current = current.Next;
      }
   }