code: def get_permissions_for_registration(self):
          
          from wagtail.wagtailsnippets.models import SNIPPET_MODELS
          if not self.is_pagemodel and self.model not in SNIPPET_MODELS:
              return self.permission_helper.get_all_model_permissions()
          return Permission.objects.none()
docs: Utilised by Wagtail's 'register_permissions' hook to allow permissions
          for a model to be assigned to groups in settings. This is only required
          if the model isn't a Page model, and isn't registered as a Snippet