docs: def state_machine_manager_notification(self, model, property, info):
          """Triggered whenever a new state machine is created, or an existing state machine is selected.
          """
          if self.current_state_machine_m is not None:
              selection = self.current_state_machine_m.selection
              if len(selection.states) > 0:
                  self.activate_state_tab(selection.get_selected_state())