Retrieve multiple Things

{
  "topic": "_/_/things/twin/commands/retrieve",
  "headers": {},
  "path": "/",
  "value": {
    "thingIds": [
      "com.acme:xdk_53",
      "com.acme:xdk_58",
      "com.acme:xdk_67"
    ]
  }
}

{
  "topic": "com.acme/_/things/twin/commands/retrieve",
  "headers": {},
  "path": "/",
  "value": [{
      "thingId": "com.acme:xdk_53",
      "policyId": "com.acme:the_policy_id",
      "attributes": {
        "location": {
          "latitude": 44.673856,
          "longitude": 8.261719
        }
      },
      "features": {
        "accelerometer": {
          "properties": {
            "x": 3.141,
            "y": 2.718,
            "z": 1,
            "unit": "g"
          }
        }
      }
    }],
  "status": 200
}