def METHOD_NAME(self, instance):
    """
    Override to_representation to add info of all notification types
    """
    value = super().METHOD_NAME(instance)
    config = value['notification_preference_config']
    for notification_app, app_prefs in config.items():
        notification_types = app_prefs.get('notification_types', {})
        for notification_type, type_prefs in notification_types.items():
            if notification_type == "core":
                type_info = COURSE_NOTIFICATION_APPS.get(notification_app, {}).get('core_info', '')
            else:
                type_info = COURSE_NOTIFICATION_TYPES.get(notification_type, {}).get('info', '')
            type_prefs['info'] = type_info
    return value