/**
         * 无向图测试
         */
        private void TestCycleGraph()
        {
            DFS  dfs = new DFS();
            Node a   = new Node("A");
            Node b   = new Node("B");
            Node c   = new Node("C");
            Node d   = new Node("D");
            Node e   = new Node("E");
            Node f   = new Node("F");
            Node g   = new Node("G");
            Node h   = new Node("H");

            dfs.AddTwoWayNodes(a, b);
            dfs.AddTwoWayNodes(b, c);
            dfs.AddTwoWayNodes(c, d);
            dfs.AddTwoWayNodes(d, a);
            dfs.AddTwoWayNodes(d, g);
            dfs.AddTwoWayNodes(a, e);
            dfs.AddTwoWayNodes(e, b);
            dfs.AddTwoWayNodes(a, f);
            dfs.AddTwoWayNodes(b, f);
            dfs.AddTwoWayNodes(b, h);
            dfs.SetHeadNode(a);
            dfs.FindCycles();
        }