code: func LowercaseSANs(sans []string) {
  	for i, san := range sans {
  		lowercase := strings.ToLower(san)
  		if lowercase != san {
  			klog.V(1).Infof("lowercasing SAN %q to %q", san, lowercase)
  			sans[i] = lowercase
  		}
  	}
  }
docs: // LowercaseSANs can be used to force all SANs to be lowercase so it passes IsDNS1123Subdomain