func AddConfigMetrics(config RefreshConfig, metrics map[charmmetrics.MetricKey]string) (RefreshConfig, error) {
	c, ok := config.(refreshOne)
	if !ok {
		return config, nil // error?
	}
	if len(metrics) < 1 {
		return c, nil
	}
	c.metrics = make(transport.ContextMetrics)
	for k, v := range metrics {
		c.metrics[k.String()] = v
	}
	return c, nil
}
// AddConfigMetrics adds metrics to a refreshOne config.  All values are
// applied at once, subsequent calls, replace all values.
AddConfigMetrics adds metrics to a refreshOne config.  All values are
applied at once, subsequent calls, replace all values.
// AddConfigMetrics adds metrics to a refreshOne config . All values are // applied at once subsequent calls replace all values .
func AddConfigMetrics(config RefreshConfig, metrics map[charmmetrics.MetricKey]string) (RefreshConfig, error) {
	c, ok := config.(refreshOne)
	if !ok {
		return config, nil 
	}
	if len(metrics) < 1 {
		return c, nil
	}
	c.metrics = make(transport.ContextMetrics)
	for k, v := range metrics {
		c.metrics[k.String()] = v
	}
	return c, nil
}
func AddConfigMetrics ( config RefreshConfig , metrics map [ charmmetrics . MetricKey ] string ) ( RefreshConfig , error ) { c , ok := config . ( refreshOne ) if ! ok { return config , nil } if len ( metrics ) < 1 { return c , nil } c . metrics = make ( transport . ContextMetrics ) for k , v := range metrics { c . metrics [ k . String ( ) ] = v } return c , nil }
AddConfigMetrics adds metrics to a refreshOne config.
AddConfigMetrics adds metrics to a refreshOne config .
// error?