public static function arrayRemoveDuplicates(&$s)
    {
        $found = [];
        $j = 0;
        foreach ($s as $i => $x) {
            if (!isset($found[$x])) {
                $found[$x] = true;
                $s[$j] = $s[$i];
                ++$j;
            }
        }
        $s = \array_slice($s, 0, $j);
    }