code: private Stream<Quad> fetchContainmentQuads() {
          if (getInteractionModel().getIRIString().endsWith("Container")) {
              final Query q = new Query();
              q.setQuerySelectType();
              q.addResultVar(OBJECT);
  
              final ElementPathBlock epb = new ElementPathBlock();
              epb.addTriple(create(OBJECT, rdf.asJenaNode(DC.isPartOf), rdf.asJenaNode(identifier)));
  
              final ElementNamedGraph ng = new ElementNamedGraph(rdf.asJenaNode(Trellis.PreferServerManaged), epb);
  
              final ElementGroup elg = new ElementGroup();
              elg.addElement(ng);
              q.setQueryPattern(elg);
  
              final Stream.Builder<Quad> builder = builder();
              rdfConnection.querySelect(q, qs -> builder.accept(rdf.createQuad(LDP.PreferContainment,
                              identifier, LDP.contains, getObject(qs))));
              return builder.build();
          }
          return Stream.empty();
      }
docs: This code is equivalent to the SPARQL query below.
  
  <p><pre><code>
  SELECT ?object
  WHERE {
  GRAPH trellis:PreferServerManaged { ?object dc:isPartOf IDENTIFIER }
  }
  </code></pre>