@Override
    public void execute(GraphModel graphModel) {
        Graph graph = graphModel.getGraphVisible();
        execute(graph);
    }
@Test
    public void testSelfLoopDirectedGraphDegree() {
        GraphModel graphModel = GraphGenerator.generateSelfLoopDirectedGraph(1);
        DirectedGraph graph = graphModel.getDirectedGraph();
        Node n = graph.getNode("0");
        WeightedDegree d = new WeightedDegree();
        d.execute(graph);
        assertEquals(n.getAttribute(WeightedDegree.WDEGREE), 2.0);
        assertEquals(n.getAttribute(WeightedDegree.WINDEGREE), 1.0);
        assertEquals(n.getAttribute(WeightedDegree.WOUTDEGREE), 1.0);
    }