code: def object_hook(self, object_dict):
      
      instance = self.decoder(object_dict)
      self.condition_list.append(instance)
      self.index += 1
      return self.index
docs: Hook which when passed into a json.JSONDecoder will replace each dict
      in a json string with its index and convert the dict to an object as defined
      by the passed in condition_decoder. The newly created condition object is
      appended to the conditions_list.
  
      Args:
        object_dict: Dict representing an object.
  
      Returns:
        An index which will be used as the placeholder in the condition_structure