/**
  * Get the associated PeriodoSc object
  *
  * @param      PropelPDO Optional Connection object.
  * @return     PeriodoSc The associated PeriodoSc object.
  * @throws     PropelException
  */
 public function getPeriodoSc(PropelPDO $con = null)
 {
     if ($this->aPeriodoSc === null && $this->periodo_id !== null) {
         $this->aPeriodoSc = PeriodoScPeer::retrieveByPk($this->periodo_id);
         /* The following can be used additionally to
         		   guarantee the related object contains a reference
         		   to this object.  This level of coupling may, however, be
         		   undesirable since it could result in an only partially populated collection
         		   in the referenced object.
         		   $this->aPeriodoSc->addTreeScs($this);
         		 */
     }
     return $this->aPeriodoSc;
 }