docs: def state_machines_del_notification(self, model, prop_name, info):
          """Relive models of closed state machine
          """
          if info['method_name'] == '__delitem__':
              state_machine_m = info["result"]
              try:
                  self.relieve_model(state_machine_m)
              except KeyError:
                  pass
              self.clean_up_tabs()