input: def create_linked_list() -> None:
      """
      Create a linked list using the Node and LinkedList classes provided.
      The linked list should have three nodes: 1, 2, and 3.
      Then, print the linked list to show the data of each node.
  
      Example:
      create_linked_list()
      1
      2
      3
      """
output:     
      class Node:
          def __init__(self, data):
              self.data = data
              self.next = None
  
      class LinkedList:
          def __init__(self):
              self.head = None
  
          def append(self, data):
              new_node = Node(data)
              if self.head is None:
                  self.head = new_node
              else:
                  current = self.head
                  while current.next:
                      current = current.next
                  current.next = new_node
  
          def print_list(self):
              current = self.head
              while current:
                  print(current.data)
                  current = current.next
  
      linked_list = LinkedList()
      linked_list.append(1)
      linked_list.append(2)
      linked_list.append(3)
      linked_list.print_list()
  