input: Write a function to implement a linked list using classes in Python. The function should define a Node class to represent individual nodes and a LinkedList class to represent the entire linked list. The LinkedList class should have a method to print the list.
  
  assert linked_list_implementation()==None
  assert print_list(linked_list.print_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 print_list(self):
          temp = self.head
          result = []
          while temp:
              result.append(temp.data)
              temp = temp.next
          return result