public function getJoinedMessage($separator = "\n")
    {
        $messages = $this->getDetailMessages();
        $array = array();
        foreach ($messages as $rules) {
            foreach ($rules as $options) {
                foreach ($options as $message) {
                    $array[] = $message;
                }
            }
        }
        return implode($separator, array_unique($array));
    }