input: 
  def reverse_double_linked_list(lst: DoubleLinkedList) -> None:
      """ Reverse the given doubly linked list in-place.
      >>> dll = DoubleLinkedList()
      >>> dll.append(1)
      >>> dll.append(2)
      >>> dll.append(3)
      >>> reverse_double_linked_list(dll)
      >>> dll.head.data
      3
      >>> dll.head.next.data
      2
      >>> dll.head.next.next.data
      1
      """
  
output:     current = lst.head
      lst.head = lst.tail
      lst.tail = current
  
      while current is not None:
          next_node = current.next
          current.next = current.prev
          current.prev = next_node
          current = next_node