code: func (v EtcdStorageVersion) String() string {
  	switch v {
  	case storageEtcd2:
  		return "etcd2"
  	case storageEtcd3:
  		return "etcd3"
  	default:
  		panic(fmt.Sprintf("enum value %d missing from EtcdStorageVersion String() function", v))
  	}
  }
docs: // String returns the text representation of the EtcdStorageVersion, 'etcd2' or 'etcd3'.