/**
  * @throws FinderException
  * @throws FinderException
  * @ejb.interface-method
  */
 public void deletePrivateInstance(long instance_pk) throws RemoteException, FinderException {
   try {
     PrivateInstanceLocal instance = privInstHome.findByPrimaryKey(new Long(instance_pk));
     PrivateSeriesLocal series = instance.getSeries();
     instance.remove();
     if (series.getInstances().isEmpty()) {
       PrivateStudyLocal study = series.getStudy();
       series.remove();
       if (study.getSeries().isEmpty()) {
         PrivatePatientLocal pat = study.getPatient();
         study.remove();
         if (pat.getStudies().isEmpty()) {
           pat.remove();
         }
       }
     }
   } catch (EJBException e) {
     throw new RemoteException(e.getMessage());
   } catch (RemoveException e) {
     throw new RemoteException(e.getMessage());
   }
 }