response.txt
Websocket query results in a set of these:

[8,"\/stops\/02113",
{"trip":{"id":"gvb:3:zkg:243:2017-12-16","number":"243","operatorKey":"gvb","operatingDate":"2017-12-16","lastCallMade":{"stopCode":"00017","stopName":"Linnaeusstraat","callOrder":3,"status":"Passed","plannedArrivalAt":"17:21:59","plannedDepartureAt":"17:22:17","delay":61,"liveArrivalAt":"17:22:56","liveDepartureAt":"17:23:18","isExtrapolated":false,"lastUpdateAt":"2017-12-16T17:24:30+01:00"}},"journey":{"id":10874,"code":"3STRH","lineId":4759,"lineNumber":"3","vehicletype":"Tram","destination":"Zoutkeetsgracht"},"calls":[{"stopCode":"02113","stopName":"Haarlemmerplein","callOrder":20,"status":"Upcoming","plannedArrivalAt":"17:55:08","plannedDepartureAt":"17:55:26","delay":0,"liveArrivalAt":"17:55:08","liveDepartureAt":"17:55:26","isExtrapolated":false,"lastUpdateAt":"2017-12-16T17:13:02+01:00"}],"time":1513441471}

{
   "time" : 1513441471,
   "trip" : {
      "number" : "243",
      "lastCallMade" : {
         "plannedArrivalAt" : "17:21:59",
         "isExtrapolated" : false,
         "callOrder" : 3,
         "liveArrivalAt" : "17:22:56",
         "plannedDepartureAt" : "17:22:17",
         "stopName" : "Linnaeusstraat",
         "lastUpdateAt" : "2017-12-16T17:24:30+01:00",
         "stopCode" : "00017",
         "liveDepartureAt" : "17:23:18",
         "delay" : 61,
         "status" : "Passed"
      },
      "id" : "gvb:3:zkg:243:2017-12-16",
      "operatorKey" : "gvb",
      "operatingDate" : "2017-12-16"
   },
   "journey" : {
      "lineNumber" : "3",
      "destination" : "Zoutkeetsgracht",
      "code" : "3STRH",
      "lineId" : 4759,
      "vehicletype" : "Tram",
      "id" : 10874
   },
   "calls" : [
      {
         "plannedDepartureAt" : "17:55:26",
         "liveArrivalAt" : "17:55:08",
         "stopName" : "Haarlemmerplein",
         "stopCode" : "02113",
         "lastUpdateAt" : "2017-12-16T17:13:02+01:00",
         "delay" : 0,
         "liveDepartureAt" : "17:55:26",
         "status" : "Upcoming",
         "plannedArrivalAt" : "17:55:08",
         "isExtrapolated" : false,
         "callOrder" : 20
      }
   ]
}