code: func (pdb *BytesBrokerWatcherEtcd) GetValue(key string) (data []byte, found bool, revision int64, err error) {
  	return getValueInternal(pdb.Logger, pdb.kv, pdb.opTimeout, key)
  }
docs: // GetValue calls 'GetValue' function of the underlying BytesConnectionEtcd.
  // KeyPrefix defined in constructor is prepended to the key argument.