registry.go
func (r *Registry) Register(name string, tags []string, v interface{}) {
	switch v.(type) {
	case Discrete, Sample:
		key := MetricID(name, tags)
		r.mutex.Lock()
		r.instruments[key] = v
		r.mutex.Unlock()
	}
}
func (r *Registry) Register(name string, tags []string, v interface{}) {
	switch v.(type) {
	case Discrete, Sample:
		key := MetricID(name, tags)
		r.mutex.Lock()
		r.instruments[key] = v
		r.mutex.Unlock()
	}
}
func ( r * Registry ) Register ( name string , tags [ ] string , v interface { } ) { switch v . ( type ) { case Discrete , Sample : key := MetricID ( name , tags ) r . mutex . Lock ( ) r . instruments [ key ] = v r . mutex . Unlock ( ) } }
// Register registers a new instrument.
Register registers a new instrument .