query VehiclePosition($id: ID!) {
  vehiclePosition(id: $id) {
    at
    latitude
    longitude
    heading
    speed {
      value
      unit
    }
    accuracy_m
    source
  }
}

{
  "id": "obj_1a2B3c"
}

{
  "data": {
    "vehiclePosition": {
      "at": "example",
      "latitude": 51.5074,
      "longitude": -0.1278,
      "heading": 1.5,
      "speed": {
        "value": 1.5,
        "unit": "kg"
      },
      "accuracy_m": 1.5,
      "source": "driver_app"
    }
  }
}