Migration of Adobe campaign to 2.0.0

I was using Adobe campaign 1.0.1 for push notification in Android and recently found that the new SDK 2.0.0 has removed AdobeCallback from registerDevice call; we are using this callback to do our logics and make necessary changes in the UI. I'm not seeing a proper alternative if we are removing this callback.

Existing implementation based on 1.0.1:

CampaignClassic.registerDevice(previousDeviceToken, userId, additionalParams, new AdobeCallback<Boolean>() {
  @Override
  public void call(final Boolean status) {
    if (status) {
      isTokenUpdatedOnServer = false;
      listener.onSuccess("Device Successfully unregistered from receiving push notifications.");
    } else {
      listener.onFailure(new MFPPushException(new Exception()));
    }
  }
});

I have seen one event dispatched during register device as per below link; but not sure how to make use of it since there is no details on how to use it.

https://developer.adobe.com/client-sdks/documentation/adobe-campaign-classic/event-reference/#events-dispatched

Can anyone give any further information on the same so that we can update the SDK to the latest one?