public static function merge(array $sids, array $newSids)
    {
        $existingSids = [];

        foreach ($sids as $sid) {
            $existingSids[] = $sid->getType().'::'.$sid->getIdentifier();
        }

        foreach ($newSids as $sid) {
            $key = $sid->getType().'::'.$sid->getIdentifier();

            if (!\in_array($key, $existingSids, true)) {
                $sids[] = $sid;
                $existingSids[] = $key;
            }
        }

        return $sids;
    }