code: func (c *Client) ListKeys(prefix string) (keyval.BytesKeyIterator, error) {
  	keys, _, err := c.client.KV().Keys(transformKey(prefix), "", nil)
  	if err != nil {
  		return nil, err
  	}
  
  	return &bytesKeyIterator{len: len(keys), keys: keys}, nil
  }
docs: // ListKeys returns interator with keys for given key prefix.