protected function thumbnailExists($thumbnailParams, $itemPath, $lastModified)
    {
        $thumbnailPath = $this->getThumbnailImagePath($thumbnailParams, $itemPath, $lastModified);

        $fullPath = temp_path(ltrim($thumbnailPath, '/'));

        if (File::exists($fullPath)) {
            return $thumbnailPath;
        }

        return false;
    }