protected function findPkComplex($key, $con)
    {
        // As the query uses a PK condition, no limit(1) is necessary.
        $criteria = $this->isKeepQuery() ? clone $this : $this;
        $stmt = $criteria
            ->filterByPrimaryKey($key)
            ->doSelect($con);

        return $criteria->getFormatter()->init($criteria)->formatOne($stmt);
    }