@Test
    public void addingEdgesWorks() {
        Vertex a = new Vertex(0);
        Vertex b = new Vertex(1);
        Edge e = new Edge(a, b);
        g.addVertex(a);
        g.addVertex(b);
        g.addEdge(a, b, 1);
        assertTrue(g.getEdges().get(0).equals(e));
    }