code: func (s *ClusterConfigurationService) GetStaticTokens() (services.StaticTokens, error) {
  	item, err := s.Get(context.TODO(), backend.Key(clusterConfigPrefix, staticTokensPrefix))
  	if err != nil {
  		if trace.IsNotFound(err) {
  			return nil, trace.NotFound("static tokens not found")
  		}
  		return nil, trace.Wrap(err)
  	}
  	return services.GetStaticTokensMarshaler().Unmarshal(item.Value,
  		services.WithResourceID(item.ID), services.WithExpires(item.Expires))
  }
docs: // GetStaticTokens gets the list of static tokens used to provision nodes.