/**
  * Retrieve object using using composite pkey values.
  * @param   string $organization_id
  * @param   int $product_id
  * @param      PropelPDO $con
  * @return   OrganizationProduct
  */
 public static function retrieveByPK($organization_id, $product_id, PropelPDO $con = null)
 {
     $_instancePoolKey = serialize(array((string) $organization_id, (string) $product_id));
     if (null !== ($obj = OrganizationProductPeer::getInstanceFromPool($_instancePoolKey))) {
         return $obj;
     }
     if ($con === null) {
         $con = Propel::getConnection(OrganizationProductPeer::DATABASE_NAME, Propel::CONNECTION_READ);
     }
     $criteria = new Criteria(OrganizationProductPeer::DATABASE_NAME);
     $criteria->add(OrganizationProductPeer::ORGANIZATION_ID, $organization_id);
     $criteria->add(OrganizationProductPeer::PRODUCT_ID, $product_id);
     $v = OrganizationProductPeer::doSelect($criteria, $con);
     return !empty($v) ? $v[0] : null;
 }