code: def prepare(self):
          
          # Maybe the Brok is a old daemon one or was already prepared
          # if so, the data is already ok
          if hasattr(self, 'prepared') and not self.prepared:
              self.data = unserialize(self.data)
              if self.instance_id:
                  self.data['instance_id'] = self.instance_id
          self.prepared = True
docs: Un-serialize data from data attribute and add instance_id key if necessary
  
          :return: None