### Question:
MemoryRepository extends JenaRepository { public void addGraph(UID context) { addGraph(context, Factory.createGraphMem()); } MemoryRepository();  MemoryRepository(Dataset dataset); void addGraph(UID context); void addGraph(UID context, Graph g);  }### Answer:
@Test public void NamedGraph_is_available() { repository.addGraph(new UID(TEST.NS)); assertNotNull(dataSource.getNamedModel(TEST.NS)); assertNotNull(dataSource.asDatasetGraph().getGraph(Node.createURI(TEST.NS))); }