code: func IsServiceUser(c context.Context) error {
  	cfg, err := GetConfigProvider(c).Config(c)
  	if err != nil {
  		return err
  	}
  	return checkMember(c, cfg.Coordinator.ServiceAuthGroup)
  }
docs: // IsServiceUser tests whether the current user belongs to the backend services
  // users group.
  //
  // If the user is not, a MembershipError will be returned.