code: func (a *AuthWithRoles) SetClusterName(c services.ClusterName) error {
  	if err := a.action(defaults.Namespace, services.KindClusterName, services.VerbCreate); err != nil {
  		return trace.Wrap(err)
  	}
  	if err := a.action(defaults.Namespace, services.KindClusterName, services.VerbUpdate); err != nil {
  		return trace.Wrap(err)
  	}
  	return a.authServer.SetClusterName(c)
  }
docs: // SetClusterName sets the name of the cluster. SetClusterName can only be called once.