code: func identifyNumLabelUnits(p *profile.Profile, ui plugin.UI) map[string]string {
  	numLabelUnits, ignoredUnits := p.NumLabelUnits()
  
  	// Print errors for tags with multiple units associated with
  	// a single key.
  	for k, units := range ignoredUnits {
  		ui.PrintErr(fmt.Sprintf("For tag %s used unit %s, also encountered unit(s) %s", k, numLabelUnits[k], strings.Join(units, ", ")))
  	}
  	return numLabelUnits
  }
docs: // identifyNumLabelUnits returns a map of numeric label keys to the units
  // associated with those keys.