code: func (c *AuthorizationService) Deactivate(authzURL string) error {
  	if len(authzURL) == 0 {
  		return errors.New("authorization[deactivate]: empty URL")
  	}
  
  	var disabledAuth acme.Authorization
  	_, err := c.core.post(authzURL, acme.Authorization{Status: acme.StatusDeactivated}, &disabledAuth)
  	return err
  }
docs: // Deactivate Deactivates an authorization.