code: def update_model(self, updates=None):
          
          if updates is None:
              return self._update_on
          assert isinstance(updates, bool), "updates are either on (True) or off (False)"
          p = getattr(self, '_highest_parent_', None)
          def turn_updates(s):
              s._update_on = updates
          p.traverse(turn_updates)
          self.trigger_update()
docs: Get or set, whether automatic updates are performed. When updates are
          off, the model might be in a non-working state. To make the model work
          turn updates on again.
  
          :param bool|None updates:
  
              bool: whether to do updates
              None: get the current update state