docs: def _setup_default_permissions(instance):
      """Separate method to conveniently call it from scripts for example."""
      from abilian.services import get_service
  
      security = get_service("security")
      for permission, roles in instance.__default_permissions__:
          if permission == "create":
              # use str for comparison instead of `abilian.services.security.CREATE`
              # symbol to avoid imports that quickly become circular.
              #
              # FIXME: put roles and permissions in a separate, isolated module.
              continue
          for role in roles:
              security.add_permission(permission, role, obj=instance)