public function removeActionMessages(...$keys) {
        $messages = $this->getAttribute(ACTION_MESSAGES_KEY);
        $dropped = [];

        foreach ($keys as $key) {
            if (isset($messages[$key]))
                $dropped[$key] = $messages[$key];
            unset($this->attributes[ACTION_MESSAGES_KEY][$key]);
        }
        if ($keys)
            return $dropped;

        unset($this->attributes[ACTION_MESSAGES_KEY]);
        return $messages;
    }