@Override
 public Model getModel(String arg0, ModelReader arg1) {
   ModelName pn = getModelName(arg0);
   if (pn != null) {
     return getNamedModel(pn);
   } else {
     return innerSource.getModel(arg0, arg1);
   }
 }
 @Override
 public Model openModelIfPresent(String arg0) {
   ModelName pn = getModelName(arg0);
   if (pn != null) {
     return getNamedModel(pn);
   } else {
     return innerSource.openModelIfPresent(arg0);
   }
 }
 @Override
 public Model createFreshModel() {
   return innerSource.createFreshModel();
 }
 @Override
 public Model createDefaultModel() {
   return innerSource.createDefaultModel();
 }