JAVA – How to access a “parent” object from object created by GSON as part of an arrayList

I have a JSON string i get from an api. Using GSON I am able to parse it into its respective objects and display it to the user.

The JSON:

{
   "status":200,
   "msg":"Event List Created.",
   "eventList":[
      {
         "eventId":124,
         "eventTitle":"My Test"
         "rooms":[
            {
               "roomId":197,
               "roomName":"Ballroom"
            },
            {
               "roomId":199,
               "roomName":"Littleroom"
            }         
         ]
      }      
   ]
}

I use two classes to allow GSON to create the objects from the string.

public class Event{
    // I create an arrayList of the room objects...
    private ArrayList<Room> rooms;
}

I tried to create a reference in the Room itself but obviously it can not be set by GSON

public class Room{
    private String roomId;
    private String roomName;
    private Event event;

    public Room(String roomId, String roomName, Event event) {
        this.roomId = roomId;
        this.roomName = roomName;
        this.event= event;
    }
}

How can I get GSON to reference the Event from each Room it creates?