public function getObjectClass($distinguishedName)
    {
        $this->utilities()->validateNotNull('Distinguished Name [dn]', $distinguishedName);

        $result = $this->search()
            ->select('objectClass')
            ->where('distinguishedName', '=', $distinguishedName)
            ->first();

        if (is_array($result) && array_key_exists('objectclass', $result)) {
            return $result['objectclass'];
        }

        return false;
    }