def notification_type(notification):
    valid_notifications = ['Command', 'Invocation']
    if (notification not in valid_notifications):
        raise ValueError(('NotificationType must be one of: "%s"' % ', '.join(valid_notifications)))
    return notification
def notification_type(notification):
    valid_notifications = ['Command', 'Invocation']
    if (notification not in valid_notifications):
        raise ValueError(('NotificationType must be one of: "%s"' % ', '.join(valid_notifications)))
    return notification