new_contents: class Node:
      def __init__(self, item, next):
          self.item = item
          self.next = next
  
  class LinkedList:
      def __init__(self):
          self.head = None
  
      def add(self, item):
          self.head = Node(item, self.head)
  
      def remove(self):
          if self.is_empty():
              return None
          else:
              item = self.head.item
              self.head = self.head.next
              return item
  
      def is_empty(self):
          return self.head == None
  
subject: Create __init__.py