func wantEdges(t *testing.T, g *Graph, edges string) {
	t.Helper()

	wantEdges := strings.Fields(edges)
	wantEdgeMap := make(map[string]bool)
	for _, e := range wantEdges {
		wantEdgeMap[e] = true
	}

	for _, n1 := range g.Nodes {
		for _, n2 := range g.Nodes {
			got := g.HasEdge(n1, n2)
			want := wantEdgeMap[n1+"->"+n2]
			if got && want {
				t.Logf("%s->%s", n1, n2)
			} else if got && !want {