protected function getNested(string $key)
    {
        $parts = explode('.', $key);
        $result = $this->settings[$parts[0]];

        for ($i = 1; $i < count($parts); ++$i) {
            $value = $parts[$i];

            if (is_array($result) && array_key_exists($value, $result)) {
                $result = $result[$value];
                continue;
            }

            $result = null;
            break;
        }

        return $result;
    }