graph.addNode();
graph.addNode();
graph.addEdge(0, 1);
graph.addEdge(0, 4);
graph.addEdge(0, 3);
graph.addEdge(3, 2);
graph.addEdge(5, 3);
Assert.assertEquals("wrong number of leaves", 4,
graph.getNumberOfLeaves());
Assert.assertEquals("wrong maximal out degree", 3, graph.getMaxOutDeg());
Assert.assertEquals("wrong number of edges", 5, graph.getEdgeNum());