old_contents: #!/usr/bin/env python
  
  from origin import OriginData
  
  class Item(OriginData):
  
      tag_name = 'item'
  
      def __init__(self, id, x, y, height, width, room, image):
          super(Item, self).__init__()
          self.id = id
          self.x = x
          self.y = y
          self.height = height
          self.width = width
          self.room = room
          self.image = image
  
new_contents: #!/usr/bin/env python
  
  from origin import OriginData
  
  class Item(OriginData):
  
      tag_name = 'item'
  
      def __init__(self, id, x, y, height, width, room, image, event):
          super(Item, self).__init__()
          self.id = id
          self.x = x
          self.y = y
          self.height = height
          self.width = width
          self.room = room
          self.image = image
          self.event = event
  
subject: add attribute event