{
  # encode data expression and extract numeric expression
  # empty configs are not accepted by Kea
  "Dhcp6": {
    "valid-lifetime": 1800,
    "client-classes": [
      # reduce literals
      {
        "name": "literal",
        /// from: match if (option dhcp6.client-data) != (encode-int(extract-int('bar', 32), 16))
        "test": "not (option[45].hex == 'ar')"
      }
    ]
  }
}