Graph.Vertex ep0 = graph.addVertex("$" + phase.name());
        Graph.Vertex ep1 = graph.addVertex("$$" + phase.name());
        Graph.Vertex ep2 = graph.addVertex(phase.name());
        Graph.Vertex ep3 = graph.addVertex("$$$" + phase.name());
        graph.addEdge(ep0, ep1);
        graph.addEdge(ep1, ep2);
        graph.addEdge(ep2, ep3);

                return gv;
            }
        }

        return null;
    }
    // ------------------------------------------------------------------------
    public MetadataGraphVertex addVertex(ArtifactMetadata md) {
        if (md == null) {
            return null;
        }

        checkVertices();

        MetadataGraphVertex v = findVertex(md);
        if (v != null) {