Predis\Cluster\ClusterStrategy::extractKeyTag PHP Метод

    protected function extractKeyTag($key)
    {
        if (false !== ($start = strpos($key, '{'))) {
            if (false !== ($end = strpos($key, '}', $start)) && $end !== ++$start) {
                $key = substr($key, $start, $end - $start);
            }
        }
        return $key;
    }