old_contents: class Node:
      node_count = 0
      bitmap = ''
      is_item = False
  
      def __init__(self, is_item, bitmap, parent, left_child, right_child):
          self.parent = parent
          self.bitmap = bitmap
          self.is_item = is_item
          self.left_child = left_child
          self.right_child = right_child
          TreeNode.node_count += 1
  
      def get_number_of_nodes(self):
          return TreeNode.node_count
  
new_contents: class Node:
      node_count = 0
      bitmap = ''
      is_item = False
  
      def __init__(self, is_item, bitmap, parent, left_child, right_child):
          self.parent = parent
          self.bitmap = bitmap
          self.is_item = is_item
          self.left_child = left_child
          self.right_child = right_child
          TreeNode.node_count += 1
  
      def get_number_of_nodes(self):
          return TreeNode.node_count
  
  class Item:
      probability = 0.0
      name = ''
      bitmap = ''
  
      def __init__(self, name, probability, bitmap):
          self.name = name
          self.probability = probability
          self.bitmap = bitmap
          return
  
subject: implement Item object