public function filterByValidUntil($validUntil = null, $comparison = null)
    {
        if (null === $comparison) {
            if (is_array($validUntil)) {
                $comparison = Criteria::IN;
            } elseif (preg_match('/[\%\*]/', $validUntil)) {
                $validUntil = str_replace('*', '%', $validUntil);
                $comparison = Criteria::LIKE;
            }
        }

        return $this->addUsingAlias(LicensePeer::VALID_UNTIL, $validUntil, $comparison);
    }