code: func (d *DNSProvider) logout() (*response, error) {
  	if d.config.AuthSid == "" {
  		return nil, fmt.Errorf("already logged out")
  	}
  
  	response, err := d.postRequest("logout", url.Values{})
  	if err == nil {
  		d.config.AuthSid = ""
  	}
  	return response, err
  }
docs: // logout closes authenticated session with Joker's DMAPI