rxgroups-android/src/main/java/com/airbnb/rxgroups/GroupLifecycleManager.java
public void onSaveInstanceState(Bundle outState) {
    hasSavedState = true;
    outState.putParcelable(KEY_STATE, new State(observableManager.id(), group.id()));
  }
public void onSaveInstanceState(Bundle outState) {
    hasSavedState = true;
    outState.putParcelable(KEY_STATE, new State(observableManager.id(), group.id()));
  }
Call this method from your Activity or Fragment's onSaveInstanceState method