public function reset(MediaInterface $media = null, $onlyFocus = false)
    {
        if ($onlyFocus === true) {
            $regex = '#^\d*x\d*_focus/';
        } else {
            $regex = '#^\d*x\d*(_focus)?/';
        }

        $regex .= ($media !== null) ? $media->getReference() : '.*';
        $regex .= '$#';

        foreach ($this->filesystemManipulator->keys() as $file) {
            if (preg_match($regex, $file)) {
                $this->filesystemManipulator->delete($file);
            }
        }
    }