code: def update_notification_list(self, apps=None, schema_editor=None, verbose=False):
          
          Notification = (apps or django_apps).get_model("edc_notification.notification")
  
          # flag all notifications as disabled and re-enable as required
          Notification.objects.all().update(enabled=False)
          if site_notifications.loaded:
              if verbose:
                  sys.stdout.write(
                      style.MIGRATE_HEADING("Populating Notification model:\n")
                  )
              self.delete_unregistered_notifications(apps=apps)
              for name, notification_cls in site_notifications.registry.items():
                  if verbose:
                      sys.stdout.write(
                          f"  * Adding '{name}': '{notification_cls().display_name}'\n"
                      )
                  try:
                      obj = Notification.objects.get(name=name)
                  except ObjectDoesNotExist:
                      Notification.objects.create(
                          name=name,
                          display_name=notification_cls().display_name,
                          enabled=True,
                      )
                  else:
                      obj.display_name = notification_cls().display_name
                      obj.enabled = True
                      obj.save()
docs: Updates the notification model to ensure all registered
          notifications classes are listed.
  
          Typically called from a post_migrate signal.
  
          Also, in tests you can register a notification and the Notification
          class (not model) will automatically call this method if the
          named notification does not exist. See notification.notify()