code: function isValidRecord(rec) {
    if (rec.v === null ||
        rec.level === null ||
        rec.name === null ||
        rec.hostname === null ||
        rec.pid === null ||
        rec.time === null ||
        rec.msg === null) {
      // Not valid Bunyan log.
      return false;
    } else {
      return true;
    }
  }
docs: Is this a valid Bunyan log record.