{
  "event": "topo2CurrentRegion",
  "payload": {
    "id": "<null-region>",
    "subregions": [{
      "id": "r2",
      "nDevs": 2
    }, {
      "id": "r1",
      "nDevs": 3
    }],
    "devices": [
      [],
      [],
      [{
        "id": "null:0000000000000001",
        "type": "switch",
        "online": false,
        "master": "",
        "layer": "def"
      }]
    ],
    "hosts": [
      [],
      [],
      []
    ],
    "links": [],
    "layerOrder": ["opt", "pkt", "def"]
  }
}