code: func expirationWarning(expiringIntermediates []int) (ret string) {
  	if len(expiringIntermediates) == 0 {
  		return
  	}
  
  	ret = expiringWarningStub
  	if len(expiringIntermediates) > 1 {
  		ret = ret + "The expiring certs are"
  	} else {
  		ret = ret + "The expiring cert is"
  	}
  	for _, index := range expiringIntermediates {
  		ret = ret + " #" + strconv.Itoa(index+1)
  	}
  	ret = ret + " in the chain."
  	return
  }
docs: // expirationWarning generates a warning message with expiring certs.