@Override
 protected void removeStatementsInternal(Resource subj, URI pred, Value obj, Resource... contexts)
     throws SailException {
   RdbmsResource s = vf.asRdbmsResource(subj);
   RdbmsURI p = vf.asRdbmsURI(pred);
   RdbmsValue o = vf.asRdbmsValue(obj);
   RdbmsResource[] c = vf.asRdbmsResource(contexts);
   triples.remove(s, p, o, c);
 }
 @Override
 protected CloseableIteration<? extends Statement, SailException> getStatementsInternal(
     Resource subj, URI pred, Value obj, boolean includeInferred, Resource... contexts)
     throws SailException {
   RdbmsResource s = vf.asRdbmsResource(subj);
   RdbmsURI p = vf.asRdbmsURI(pred);
   RdbmsValue o = vf.asRdbmsValue(obj);
   RdbmsResource[] c = vf.asRdbmsResource(contexts);
   return triples.find(s, p, o, c);
 }