function getSpanStatusFromHttpCode(httpStatus) {
  if (httpStatus < 400 && httpStatus >= 100) {
    return 'ok';
  }

  if (httpStatus >= 400 && httpStatus < 500) {
    switch (httpStatus) {
      case 401:
        return 'unauthenticated';
      case 403:
        return 'permission_denied';
      case 404:
        return 'not_found';
      case 409:
        return 'already_exists';
      case 413:
        return 'failed_precondition';
      case 429:
        return 'resource_exhausted';
      default:
        return 'invalid_argument';
    }
  }

  if (httpStatus >= 500 && httpStatus < 600) {
    switch (httpStatus) {
      case 501:
        return 'unimplemented';
      case 503:
        return 'unavailable';
      case 504:
        return 'deadline_exceeded';
      default:
        return 'internal_error';
    }
  }

  return 'unknown_error';
}
Converts a HTTP status code into a {@link SpanStatusType}.

@param httpStatus The HTTP response status code.
@returns The span status or unknown_error.