private void validateInputData(ListNode node) {
    if (node == null) {
      throw new IllegalArgumentException(
          "You can't pass a null instance of ListNode as parameter.");
    }
  }
Iterative algorithm to solve this problem. We don't have access to the head of the list, and
the only thing we can do is to move the data from the next node to the current one, the data
and the pointer to the next node. This approach doesn't work with the last element in the
list, but there is no another valid approach to solve this algorithm without access to the
head of the list.
src/main/java/com/github/pedrovgs/problem59/DeleteListNode.java