metrics

type Map interface {
	// Add adds a new metric to the map.
	Add(key string, delta int64)

	// AddFloat adds a new metric to the map.
	AddFloat(key string, delta float64)

	// Get gets a Var from the Map.
	Get(key string) expvar.Var
}

type Metrics interface {
	NewCounter(name string) func(delta uint64)
	NewGauge(name string) func(value float64)
}