Metrics = newDialMetrics()
)

// DialMetrics instruments dials to proxy server with prometheus metrics.
type DialMetrics struct {
	clock     clock.Clock
	starts    *metrics.CounterVec
	latencies *metrics.HistogramVec
	failures  *metrics.CounterVec
}

// newDialMetrics create a new DialMetrics, configured with default metric names.
func newDialMetrics() *DialMetrics {