private function mergeLists(array $blacklist, array $whitelist) : array
    {
        if (count(array_intersect($blacklist, $whitelist)) !== 0) {
            throw new LogicException('Directories can\'t be black- and whitelisted at the same time', 1553780055);
        }

        return array_merge(
            array_fill_keys($blacklist, false),
            array_fill_keys($whitelist, true)
        );
    }