code: func (pdb *BrokerWatcher) ListValues(key string) (keyval.BytesKeyValIterator, error) {
  	pairs, _, err := pdb.client.KV().List(pdb.prefixKey(key), nil)
  	if err != nil {
  		return nil, err
  	}
  
  	return &bytesKeyValIterator{len: len(pairs), pairs: pairs, prefix: pdb.prefix}, nil
  }
docs: // ListValues calls 'ListValues' function of the underlying BytesConnectionEtcd.
  // KeyPrefix defined in constructor is prepended to the key argument.
  // The prefix is removed from the keys of the returned values.