@Override
    public void addEventToUserFollowedEvents(Event event, AuthenticatedUser user) {
        userCollection.document(user.getSciper()).update("followed_events", FieldValue.arrayUnion(event.getId()));
        userCollection.document(user.getSciper()).update("followed_channels", FieldValue.arrayUnion(event.getChannelId()));
        eventCollection.document(event.getId()).update("followers", FieldValue.arrayUnion(user.getSciper()));