rocket.chat.mqtt/node_modules/mongodb-core/lib/utils.js

It's a MQTT Server, using redis to scale horizontally.

'use strict';

const crypto = require('crypto');

const uuidV4 = () => {
  const result = crypto.randomBytes(16);
  result[6] = (result[6] & 0x0f) | 0x40;
  result[8] = (result[8] & 0x3f) | 0x80;
  return result;
};

module.exports = {
  uuidV4: uuidV4
};