convenience.go
func (r *Registry) Counter(name string, tags []string) *Counter {
	return r.fetchCounter(name, tags, newCounter)
}
func (r *Registry) Counter(name string, tags []string) *Counter {
	return r.fetchCounter(name, tags, newCounter)
}
func ( r * Registry ) Counter ( name string , tags [ ] string ) * Counter { return r . fetchCounter ( name , tags , newCounter ) }
// Counter fetches an instrument from the registry or creates a new one.
//
// If another instrument type is already registered with the same
// name/tags, a blank one will be returned and an error
// will be logged to the Errors() channel.
Counter fetches an instrument from the registry or creates a new one . If another instrument type is already registered with the same name / tags a blank one will be returned and an error will be logged to the Errors () channel .