input: Write a function to delete a certain element from a linked list. The function should take a linked list and the node to be deleted as input, and modify the linked list to remove the specified node. If the node is not present in the linked list, the function should do nothing.
  assert deleteNode(LinkedList(), None) == None
  assert deleteNode(createLinkedList([1, 2, 3]), 2) == [1, 3]
  assert deleteNode(createLinkedList([4, 5, 6]), 4) == [5, 6]
  assert deleteNode(createLinkedList([7, 8, 9]), 9) == [7, 8]
  assert deleteNode(createLinkedList([10]), 10) == []
  assert deleteNode(createLinkedList([11, 12, 13]), 14) == [11, 12, 13]
output: def deleteNode(linked_list, node):
      if not linked_list or not node:
          return linked_list
      
      if linked_list.val == node:
          return linked_list.next
      
      current = linked_list
      while current.next:
          if current.next.val == node:
              current.next = current.next.next
              return linked_list
          current = current.next
      
      return linked_list