code: func isAtomic(req *http.Request) (bool, error) {
  	// "transaction" is checked for backwards compatibility with
  	// client libraries.
  	for _, q := range []string{"atomic", "transaction"} {
  		if a, err := queryParam(req, q); err != nil || a {
  			return a, err
  		}
  	}
  	return false, nil
  }
docs: // isAtomic returns whether the HTTP request is an atomic request.