code: function OneTimeToken (options) {
    this._id = options._id || crypto.randomBytes(32).toString('hex')
    this.exp = options.exp
    this.use = options.use
    this.sub = options.sub
  
    if (options.ttl) {
      this.exp = Math.round(Date.now() / 1000) + options.ttl
    }
  }
docs: OneTimeToken
  
  OneTimeToken is an expiring (TTL) token class
  used for any process that requires an expiring
  token such as email verification and password
  reset.
  
  The constructor generates a random string suitable
  for use as a public token, and stores metadata
  such as when the token expires, what the token
  should be used for, and the identifier of the
  subject in question (user, client, etc).