code: func (cm *CheckManager) addNewMetrics(newMetrics map[string]*api.CheckBundleMetric) bool {
  	updatedCheckBundle := false
  
  	if cm.checkBundle == nil || len(newMetrics) == 0 {
  		return updatedCheckBundle
  	}
  
  	cm.cbmu.Lock()
  	defer cm.cbmu.Unlock()
  
  	numCurrMetrics := len(cm.checkBundle.Metrics)
  	numNewMetrics := len(newMetrics)
  
  	if numCurrMetrics+numNewMetrics >= cap(cm.checkBundle.Metrics) {
  		nm := make([]api.CheckBundleMetric, numCurrMetrics+numNewMetrics)
  		copy(nm, cm.checkBundle.Metrics)
  		cm.checkBundle.Metrics = nm
  	}
  
  	cm.checkBundle.Metrics = cm.checkBundle.Metrics[0 : numCurrMetrics+numNewMetrics]
  
  	i := 0
  	for _, metric := range newMetrics {
  		cm.checkBundle.Metrics[numCurrMetrics+i] = *metric
  		i++
  		updatedCheckBundle = true
  	}
  
  	if updatedCheckBundle {
  		cm.forceCheckUpdate = true
  	}
  
  	return updatedCheckBundle
  }
docs: // addNewMetrics updates a check bundle with new metrics