docs: function parseRetryAfter(retryAfter) {
      // Only parse once
      if (typeof retryAfter === 'number') {
          return retryAfter;
      } else if (isNaN(retryAfter)) {
        return Math.ceil((new Date(retryAfter).getTime() / 1000) - Date.now() / 1000);
      } else {
        return parseInt(retryAfter, 10); 
      }
  }