code: func (c *statCollector) Update(ch chan<- prometheus.Metric) error {
  	var fieldsCount = 5
  	cpuTimes, err := getDragonFlyCPUTimes()
  	if err != nil {
  		return err
  	}
  
  	// Export order: user nice sys intr idle
  	cpuFields := []string{"user", "nice", "sys", "interrupt", "idle"}
  	for i, value := range cpuTimes {
  		cpux := fmt.Sprintf("%d", i/fieldsCount)
  		ch <- prometheus.MustNewConstMetric(c.cpu, prometheus.CounterValue, value, cpux, cpuFields[i%fieldsCount])
  	}
  
  	return nil
  }
docs: // Expose CPU stats using sysctl.