    @Test
    public void testSetNamespaces() {

        Map<String, String> namespaces = new HashMap<String, String>();
        namespaces.put("dummy", "http://dummy");

        boolean forceReload = false;
        Model jenaGraph = graph.openGraph(forceReload).getGraph();
        Map<String, String> map = jenaGraph.getNsPrefixMap();
        // old namespaces are kept
        assertEquals("http://www.w3.org/1999/02/22-rdf-syntax-ns#",
                map.get("rdf"));
        assertEquals("http://purl.org/dc/terms/", map.get("dcterms"));
        assertNull(map.get("dummy"));

        GraphDescriptor desc = new GraphDescriptor();
        desc.namespaces = namespaces;
        graph.setDescription(desc);

        // not set yet on the graph, have to rebuild it
        jenaGraph = graph.openGraph(forceReload).getGraph();
        map = jenaGraph.getNsPrefixMap();
        assertEquals("http://www.w3.org/1999/02/22-rdf-syntax-ns#",
                map.get("rdf"));
        assertEquals("http://purl.org/dc/terms/", map.get("dcterms"));
        assertNull(map.get("dummy"));

        // rebuild graph
        forceReload = true;
        jenaGraph = graph.openGraph(forceReload).getGraph();
        map = jenaGraph.getNsPrefixMap();
        // old namespaces are still set on the named graph lots
        assertNull(map.get("rdf"));
        assertNull(map.get("dcterms"));
        assertEquals("http://dummy", map.get("dummy"));
    }