/**
  * Test ClassDiagramRenderer lookup mechanism for resolving model element types to a Fig which can
  * be added to the diagram.
  */
 public void testClassDiagramRenderer() {
   UMLClassDiagram diagram = new UMLClassDiagram();
   ClassDiagramRenderer renderer = new ClassDiagramRenderer();
   GraphModel gm = new ClassDiagramGraphModel();
   for (int i = 0; i < nodeTypes.length; i++) {
     Fig fig = renderer.getFigNodeFor(gm, diagram.getLayer(), nodeTypes[i], Collections.EMPTY_MAP);
     assertNotNull("failed to get Fig for " + nodeTypes[i], fig);
     diagram.add(fig);
   }
 }
 /**
  * Test the UMLClassDiagram empty constructor. The graph model should always be a
  * ClassDiagramGraphModel
  */
 public void testUMLClassDiagram() {
   UMLClassDiagram diagram = new UMLClassDiagram();
   assertTrue(diagram.getGraphModel() instanceof ClassDiagramGraphModel);
 }