Edge cd1 = new SimpleEdge(c, d, 1, 1);
Edge cd2 = new SimpleEdge(c, d, 2, 2);
Edge cd3 = new SimpleEdge(c, d, 3, 3);
OverlayGraph og = new OverlayGraph(g);
assertEquals(g.countVertices(), og.countVertices());
assertEquals(g.countEdges(), og.countEdges());
for (Vertex v : g.getVertices()) {
for (Edge e : v.getOutgoing()) {
assertTrue(og.getOutgoing(v).contains(e));
assertTrue(og.getIncoming(e.getToVertex()).contains(e));
}