protected function getEmbedlyCache(string $url)
    {
        $cache_dir = $this->cache_dir.'/embedly';
        $cache_dir .= '/'.$this->c::sha1ModShardId($url);
        $cache_file = $cache_dir.'/'.sha1($url);

        if (is_file($cache_file)) {
            $embed = file_get_contents($cache_file);
            $embed = unserialize($embed);
            if ($embed instanceof \StdClass) {
                return $embed;
            }
        }
    }