code: func ConfigFromBackend(coreBackend ...core.ConfigBackend) (MetricsConfig, error) {
  	//create default metrics config
  	config := &MetricsConfigImpl{backend: lookup.New(coreBackend...)}
  	//operationsConfig
  	if err := config.loadMetricsConfiguration(); err != nil {
  		return nil, errors.WithMessage(err, "metrics configuration load failed")
  	}
  	return config, nil
  }
docs: //ConfigFromBackend returns identity config implementation of given backend