type Counter struct{}
func (c *Counter) Add(delta float64)
func (c *Counter) With(labelValues ...string) metrics.Counter
type Gauge struct{}
func (g *Gauge) Add(delta float64)
func (g *Gauge) Set(delta float64)
func (g *Gauge) With(labelValues ...string) metrics.Gauge
type Histogram struct{}
func (h *Histogram) Observe(value float64)
func (h *Histogram) With(labelValues ...string) metrics.Histogram
type Provider struct{}
func (p *Provider) NewCounter(o metrics.CounterOpts) metrics.Counter
func (p *Provider) NewGauge(o metrics.GaugeOpts) metrics.Gauge
func (p *Provider) NewHistogram(o metrics.HistogramOpts) metrics.Histogram