public function getProductCategory($con = null)
 {
     if ($this->aProductCategory === null && $this->id !== null) {
         include_once 'lib/model/om/BaseProductCategoryPeer.php';
         $this->aProductCategory = ProductCategoryPeer::retrieveByPK($this->id, $con);
     }
     return $this->aProductCategory;
 }