registry.go
func (r *Registry) Get(name string, tags []string) interface{} {
	key := MetricID(name, tags)
	r.mutex.RLock()
	v := r.instruments[key]
	r.mutex.RUnlock()
	return v
}
func (r *Registry) Get(name string, tags []string) interface{} {
	key := MetricID(name, tags)
	r.mutex.RLock()
	v := r.instruments[key]
	r.mutex.RUnlock()
	return v
}
func ( r * Registry ) Get ( name string , tags [ ] string ) interface { } { key := MetricID ( name , tags ) r . mutex . RLock ( ) v := r . instruments [ key ] r . mutex . RUnlock ( ) return v }
// Get returns an instrument from the Registry.
Get returns an instrument from the Registry .