@Override
 public CloseableIteration<? extends Statement, SailException> getStatements(
     Resource subj, IRI pred, Value obj, Resource... contexts) throws SailException {
   observer.observe(subj, pred, obj, contexts);
   return super.getStatements(subj, pred, obj, contexts);
 }
 @Override
 public CloseableIteration<? extends Resource, SailException> getContextIDs()
     throws SailException {
   observer.observe(null, null, null);
   return super.getContextIDs();
 }