code: func (c *customMetricsClient) GetRawMetric(metricName string, namespace string, selector labels.Selector, metricSelector labels.Selector) (PodMetricsInfo, time.Time, error) {
  	metrics, err := c.client.NamespacedMetrics(namespace).GetForObjects(schema.GroupKind{Kind: "Pod"}, selector, metricName, metricSelector)
  	if err != nil {
  		return nil, time.Time{}, fmt.Errorf("unable to fetch metrics from custom metrics API: %v", err)
  	}
  
  	if len(metrics.Items) == 0 {
  		return nil, time.Time{}, fmt.Errorf("no metrics returned from custom metrics API")
  	}
  
  	res := make(PodMetricsInfo, len(metrics.Items))
  	for _, m := range metrics.Items {
  		window := metricServerDefaultMetricWindow
  		if m.WindowSeconds != nil {
  			window = time.Duration(*m.WindowSeconds) * time.Second
  		}
  		res[m.DescribedObject.Name] = PodMetric{
  			Timestamp: m.Timestamp.Time,
  			Window:    window,
  			Value:     int64(m.Value.MilliValue()),
  		}
  
  		m.Value.MilliValue()
  	}
  
  	timestamp := metrics.Items[0].Timestamp.Time
  
  	return res, timestamp, nil
  }
docs: // GetRawMetric gets the given metric (and an associated oldest timestamp)
  // for all pods matching the specified selector in the given namespace