/**
  * If this collection has already been initialized with
  * an identical criteria, it returns the collection.
  * Otherwise if this BpmnProject has previously
  * been saved, it will retrieve related BpmnParticipants from storage.
  * If this BpmnProject is new, it will return
  * an empty collection or the current collection, the criteria
  * is ignored on a new object.
  *
  * @param      Connection $con
  * @param      Criteria $criteria
  * @throws     PropelException
  */
 public function getBpmnParticipants($criteria = null, $con = null)
 {
     // include the Peer class
     include_once 'classes/model/om/BaseBpmnParticipantPeer.php';
     if ($criteria === null) {
         $criteria = new Criteria();
     } elseif ($criteria instanceof Criteria) {
         $criteria = clone $criteria;
     }
     if ($this->collBpmnParticipants === null) {
         if ($this->isNew()) {
             $this->collBpmnParticipants = array();
         } else {
             $criteria->add(BpmnParticipantPeer::PRJ_UID, $this->getPrjUid());
             BpmnParticipantPeer::addSelectColumns($criteria);
             $this->collBpmnParticipants = BpmnParticipantPeer::doSelect($criteria, $con);
         }
     } else {
         // criteria has no effect for a new object
         if (!$this->isNew()) {
             // the following code is to determine if a new query is
             // called for.  If the criteria is the same as the last
             // one, just return the collection.
             $criteria->add(BpmnParticipantPeer::PRJ_UID, $this->getPrjUid());
             BpmnParticipantPeer::addSelectColumns($criteria);
             if (!isset($this->lastBpmnParticipantCriteria) || !$this->lastBpmnParticipantCriteria->equals($criteria)) {
                 $this->collBpmnParticipants = BpmnParticipantPeer::doSelect($criteria, $con);
             }
         }
     }
     $this->lastBpmnParticipantCriteria = $criteria;
     return $this->collBpmnParticipants;
 }