public function getDatasetVersion()
 {
     if ($this->_datasetVersion === null) {
         $dvers = new Default_Model_DatasetVersions();
         $dvers->filter->id->equals($this->getDatasetVersionID());
         if ($dvers->count() > 0) {
             $this->_datasetVersion = $dvers->items[0];
         }
     }
     return $this->_datasetVersion;
 }
 public function getParent()
 {
     if ($this->_parent === null) {
         $ds = new Default_Model_DatasetVersions();
         $ds->filter->id->equals($this->getParentID());
         if ($ds->count() > 0) {
             $this->_parent = $ds->items[0];
         }
     }
     return $this->_parent;
 }