code: func requestRetryable(req *http.Request, resp *http.Response) bool {
  	idempotent := req.Method == "GET" || req.Method == "HEAD"
  	return idempotent && resp.StatusCode == 401
  }
docs: // Returns true if the request is retryable. Only idempotent requests that
  // return a 401 are retried.
  //
  // This is done to address an issue in the GitHub API, where newly create auth
  // tokens aren't immediately available, presumably because GitHub uses a read
  // replica.
  //
  // See https://github.com/remind101/empire/issues/1026