Answer <code>model</code> after updating it with the sub-graph of
<code>s</code> rooted at <code>r</code>, bounded by this instances
<code>boundary</code>.
*/
public Model extractInto( Model model, Resource r, Model s )
{ TripleBoundary tb = boundary.asTripleBoundary( s );
Graph g = getGraphExtract( tb ) .extractInto( model.getGraph(), r.asNode(), s.getGraph() );
return ModelFactory.createModelForGraph( g ); }