Take care of cascade=true in purgeObs in ObsServiceImpl.java

@Override
 public void purgeObs(Obs obs, boolean cascade) throws APIException {
  if (!purgeComplexData(obs)) {
   throw new APIException("Obs.error.unable.purge.complex.data", new Object[] { obs });
  }
  
  if (cascade) {
   throw new APIException("Obs.error.cascading.purge.not.implemented", (Object[]) null);
   // TODO delete any related objects here before deleting the obs
   // obsGroups objects?
   // orders?
  }
  
  dao.deleteObs(obs);
 }