{
  # hardware data expression
  # empty configs are not accepted by Kea
  "Dhcp4": {
    "valid-lifetime": 1800,
    "client-classes": [
      # pretty standard hardware superclass
      /// match: hardware
      {
        "name": "byhw"
      },
      /// subclass selector 0x0x0100070e364819
      {
        "name": "sub#byhw#0",
        "option-data": [
          {
            "space": "dhcp4",
            "name": "host-name",
            "code": 12,
            "data": "test1"
          }
        ],
        /// from: match hardware
        /// data: 0x0100070e364819
        "test": "concat(substring(pkt4.htype,-1,all), pkt4.mac) == 0x0100070e364819"
      }
    ],
    "option-data": [
//    # raw
//    {
//      "space": "dhcp4",
//      "name": "host-name",
//      "code": 12,
//      "csv-format": false,
//      "expression": {
//        "binary-to-ascii": {
//          "base": 16,
//          "width": 8,
//          "separator": "-",
//          "buffer": {
//            "concat": {
//              "left": {
//                "hw-type": null
//              },
//              "right": {
//                "hw-address": null
//              }
//            }
//          }
//        }
//      }
//    }
    ]
  }
}