code: func (r *AlertingRule) forStateSample(alert *Alert, ts time.Time, v float64) promql.Sample {
  	lb := labels.NewBuilder(r.labels)
  
  	for _, l := range alert.Labels {
  		lb.Set(l.Name, l.Value)
  	}
  
  	lb.Set(labels.MetricName, alertForStateMetricName)
  	lb.Set(labels.AlertName, r.name)
  
  	s := promql.Sample{
  		Metric: lb.Labels(),
  		Point:  promql.Point{T: timestamp.FromTime(ts), V: v},
  	}
  	return s
  }
docs: // forStateSample returns the sample for ALERTS_FOR_STATE.