Return users list from pubnub to an array list

Question

This is my code.

ArrayList<String> usr = new ArrayList<>();
mypubnub.hereNow()
        .channels(Collections.singletonList(channel_name))
        .includeUUIDs(true)
        .async(new PNCallback<PNHereNowResult>() {
            @Override
            public void onResponse(PNHereNowResult result, PNStatus status) {
                try {
                    JSONObject object = new JSONObject(result.getChannels());
                    JSONArray jsonArray = object.getJSONArray("uuids");
                    for (int i = 0; i < jsonArray.length(); i++) {
                        usr.add(jsonArray.getString(i));
                    }
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        });

How can i create the list with online users name from PNHereNowResult result?

new JSONObject(result.getChannels()) does't work.

It says that can't be converted to an object.