public void DeepCopyGraph()
{
// a cube
var graph = new DirectedGraph(4);
graph.AddEdge(0, 1);
graph.AddEdge(1, 2);
graph.AddEdge(2, 3);
graph.AddEdge(3, 0);
graph.AddEdge(0, 2);
graph.AddEdge(3, 3);
var graph2 = graph.DeepCopy();
Assert.AreEqual(graph.ToString(), graph2.ToString());
Assert.AreNotSame(graph, graph2);
}