code: func (c *Client) Watch(resp func(keyval.BytesWatchResp), closeChan chan string, keys ...string) error {
  	boltLogger.Debugf("Watch: %q", keys)
  	for _, k := range keys {
  		if err := c.watch(resp, closeChan, k); err != nil {
  			return err
  		}
  	}
  	return nil
  }
docs: // Watch watches given list of key prefixes.