private function notifyProgress()
 {
     if ($this->destination instanceof ProgressListenerInterface) {
         $this->destination->afterObjectProcessed();
     }
 }
 /**
  * @param \Iterator $destinationObjects
  */
 private function setUpDestinationToReturn(\Iterator $destinationObjects)
 {
     $this->destination->expects($this->any())->method('getObjectsOrderedById')->will($this->returnValue($destinationObjects));
 }