protected function artFile($art)
    {
        $files = $this->fileSearch($art, '[^' . \DIRECTORY_SEPARATOR . ']*$');

        if (count($files) === 0) {
            $this->addDir(__DIR__ . '/../../ASCII');
            $files = $this->fileSearch($this->default_art, '.*');
        }

        if (count($files) === 0) {
            throw new UnexpectedValueException("Unable to find an art file with the name '{$art}'");
        }

        return reset($files);
    }