Operation operation = new Operation();
IArtefactRepresentation artefact = operation.process(model, null);
Assert.assertNotNull(artefact);
EcoreToolsGMFDiagramURI diagram = (EcoreToolsGMFDiagramURI) artefact;
String fileName = diagram.getDiagramURI().toFileString();
File file = new File(fileName);
Assert.assertTrue(file.exists());
Assert.assertTrue(file.getTotalSpace() > 0);