code: func (db *BytesConnectionEtcd) GetValueRev(key string, rev int64) (data []byte, found bool, revision int64, err error) {
  	return getValueRevInternal(db.Logger, db.etcdClient, db.opTimeout, key, rev)
  }
docs: // GetValueRev retrieves one key-value item from the data store. The item
  // is identified by the provided <key>.