func GetOrRegisterTimeSeries(name string, r Metrics) TimeSeries {
	return r.GetOrRegister(name, NewTimeSeries).(TimeSeries)
}
GetOrRegisterTimer returns an existing Timer or constructs and registers a
new StandardTimer.
Be sure to unregister the meter from the registry once it is of no use to
allow for garbage collection.
package metrics
import (
	"sync"
	"time"
)
type TimeSeries interface {
	Cumulative() time.Duration  
	HMean() time.Duration       
	Avg() time.Duration         
	P50() time.Duration         
	P75() time.Duration
	P95() time.Duration
	P99() time.Duration
	P999() time.Duration
	Long5p() time.Duration   
	Short5p() time.Duration  
	Max() time.Duration      
	Min() time.Duration      
	StdDev() time.Duration   
	Range() time.Duration    
	Time(func())
	AddTime(time.Duration)
	SetWallTime(time.Duration)
	Snapshot() TimeSeries
}