code: func (c *Client) FormatError(e ErrEntry) string {
  	return fmt.Sprintf("%d %s [%s] %s request-%d retry-%d error: %s\n",
  		e.Time.Unix(), e.Method, e.Verb, e.URL, e.Request, e.Retry, e.Err)
  }
docs: // Format the Error to human readable string