code: func ParseEtcdStorageVersion(s string) (EtcdStorageVersion, error) {
  	switch s {
  	case "etcd2":
  		return storageEtcd2, nil
  	case "etcd3":
  		return storageEtcd3, nil
  	default:
  		return storageUnknown, fmt.Errorf("unrecognized storage version: %s", s)
  	}
  }
docs: // ParseEtcdStorageVersion parses an etcd storage version string to an EtcdStorageVersion.