      "        print('Success: test_graph')\n",
      "\n",
      "    def test_graph_undirected(self):\n",
      "        graph = self.create_graph()\n",
      "\n",
      "        graph.add_undirected_edge(0, 1, weight=5)\n",
      "        graph.add_undirected_edge(0, 5, weight=2)\n",
      "        graph.add_undirected_edge(1, 2, weight=3)\n",
      "\n",
      "        assert_equal(graph.nodes[0].adjacent[graph.nodes[1]], 5)\n",
 
</s> remove     "\n",
 </s> add  </s> remove     "        assert_equal(graph.nodes[0].adjacent[graph.nodes[1]], 5)\n",
    "        assert_equal(graph.nodes[1].adjacent[graph.nodes[0]], 5)\n",
    "        assert_equal(graph.nodes[0].adjacent[graph.nodes[5]], 2)\n",
    "        assert_equal(graph.nodes[5].adjacent[graph.nodes[0]], 2)\n",
    "        assert_equal(graph.nodes[1].adjacent[graph.nodes[2]], 3)\n",
    "        assert_equal(graph.nodes[2].adjacent[graph.nodes[1]], 3)\n",
 </s> add     "        assert_equal(graph.nodes[0].adj_weights[graph.nodes[1].key], 5)\n",
    "        assert_equal(graph.nodes[1].adj_weights[graph.nodes[0].key], 5)\n",
    "        assert_equal(graph.nodes[0].adj_weights[graph.nodes[5].key], 2)\n",
    "        assert_equal(graph.nodes[5].adj_weights[graph.nodes[0].key], 2)\n",
    "        assert_equal(graph.nodes[1].adj_weights[graph.nodes[2].key], 3)\n",
    "        assert_equal(graph.nodes[2].adj_weights[graph.nodes[1].key], 3)\n", </s> remove     "        assert_equal(graph.nodes[0].adjacent[graph.nodes[1]], 5)\n",
    "        assert_equal(graph.nodes[1].adjacent[graph.nodes[0]], 5)\n",
    "        assert_equal(graph.nodes[0].adjacent[graph.nodes[5]], 2)\n",
    "        assert_equal(graph.nodes[5].adjacent[graph.nodes[0]], 2)\n",
    "        assert_equal(graph.nodes[1].adjacent[graph.nodes[2]], 3)\n",
    "        assert_equal(graph.nodes[2].adjacent[graph.nodes[1]], 3)\n",
 </s> add     "        assert_equal(graph.nodes[0].adj_weights[graph.nodes[1].key], 5)\n",
    "        assert_equal(graph.nodes[1].adj_weights[graph.nodes[0].key], 5)\n",
    "        assert_equal(graph.nodes[0].adj_weights[graph.nodes[5].key], 2)\n",
    "        assert_equal(graph.nodes[5].adj_weights[graph.nodes[0].key], 2)\n",
    "        assert_equal(graph.nodes[1].adj_weights[graph.nodes[2].key], 3)\n",
    "        assert_equal(graph.nodes[2].adj_weights[graph.nodes[1].key], 3)\n", </s> remove     "\n",
 </s> add  </s> remove     "\n",
 </s> add 
      "        print('Success: test_graph')\n",
      "\n",
      "    def test_graph_undirected(self):\n",
      "        graph = self.create_graph()\n",

      "        graph.add_undirected_edge(0, 1, weight=5)\n",
      "        graph.add_undirected_edge(0, 5, weight=2)\n",
      "        graph.add_undirected_edge(1, 2, weight=3)\n",
      "\n",
      "        assert_equal(graph.nodes[0].adjacent[graph.nodes[1]], 5)\n",
keep keep keep keep replace keep keep keep keep keep
 Rework graph challenge and solution (#90) 
graphs_trees/graph/graph_challenge.ipynb