          assert_equal(graph.nodes[5].adjacent[graph.nodes[0]], 2)
          assert_equal(graph.nodes[1].adjacent[graph.nodes[2]], 3)
          assert_equal(graph.nodes[2].adjacent[graph.nodes[1]], 3)
  
          print('Success: test_graph')
  
  
  def main():
      test = TestGraph()
      test.test_graph()
 
</s> remove         assert_equal(graph.nodes[0].adjacent[graph.nodes[1]], 5)
        assert_equal(graph.nodes[1].adjacent[graph.nodes[0]], 5)
        assert_equal(graph.nodes[0].adjacent[graph.nodes[5]], 2)
        assert_equal(graph.nodes[5].adjacent[graph.nodes[0]], 2)
        assert_equal(graph.nodes[1].adjacent[graph.nodes[2]], 3)
        assert_equal(graph.nodes[2].adjacent[graph.nodes[1]], 3)
 </s> add         assert_equal(graph.nodes[0].adj_weights[graph.nodes[1].key], 5)
        assert_equal(graph.nodes[1].adj_weights[graph.nodes[0].key], 5)
        assert_equal(graph.nodes[0].adj_weights[graph.nodes[5].key], 2)
        assert_equal(graph.nodes[5].adj_weights[graph.nodes[0].key], 2)
        assert_equal(graph.nodes[1].adj_weights[graph.nodes[2].key], 3)
        assert_equal(graph.nodes[2].adj_weights[graph.nodes[1].key], 3) </s> remove         assert_equal(graph.nodes[0].adjacent[graph.nodes[1]], 5)
        assert_equal(graph.nodes[0].adjacent[graph.nodes[5]], 2)
        assert_equal(graph.nodes[1].adjacent[graph.nodes[2]], 3)
        assert_equal(graph.nodes[2].adjacent[graph.nodes[3]], 4)
        assert_equal(graph.nodes[3].adjacent[graph.nodes[4]], 5)
        assert_equal(graph.nodes[3].adjacent[graph.nodes[5]], 6)
        assert_equal(graph.nodes[4].adjacent[graph.nodes[0]], 7)
        assert_equal(graph.nodes[5].adjacent[graph.nodes[4]], 8)
        assert_equal(graph.nodes[5].adjacent[graph.nodes[2]], 9)
 </s> add         assert_equal(graph.nodes[0].adj_weights[graph.nodes[1].key], 5)
        assert_equal(graph.nodes[0].adj_weights[graph.nodes[5].key], 2)
        assert_equal(graph.nodes[1].adj_weights[graph.nodes[2].key], 3)
        assert_equal(graph.nodes[2].adj_weights[graph.nodes[3].key], 4)
        assert_equal(graph.nodes[3].adj_weights[graph.nodes[4].key], 5)
        assert_equal(graph.nodes[3].adj_weights[graph.nodes[5].key], 6)
        assert_equal(graph.nodes[4].adj_weights[graph.nodes[0].key], 7)
        assert_equal(graph.nodes[5].adj_weights[graph.nodes[4].key], 8)
        assert_equal(graph.nodes[5].adj_weights[graph.nodes[2].key], 9)

        assert_equal(graph.nodes[0].incoming_edges, 1)
        assert_equal(graph.nodes[1].incoming_edges, 1)
        assert_equal(graph.nodes[2].incoming_edges, 2)
        assert_equal(graph.nodes[3].incoming_edges, 1)
        assert_equal(graph.nodes[4].incoming_edges, 2)
        assert_equal(graph.nodes[5].incoming_edges, 2)

        graph.nodes[0].remove_neighbor(graph.nodes[1])
        assert_equal(graph.nodes[1].incoming_edges, 0)
        graph.nodes[3].remove_neighbor(graph.nodes[4])
        assert_equal(graph.nodes[4].incoming_edges, 1)

        assert_equal(graph.nodes[0] < graph.nodes[1], True) </s> remove     "        print('Success: test_graph')\n",
 </s> add     "        print('Success: test_graph_undirected')\n", </s> remove     "        print('Success: test_graph')\n",
 </s> add     "        print('Success: test_graph_undirected')\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",
        print('Success: test_graph_undirected')
          assert_equal(graph.nodes[5].adjacent[graph.nodes[0]], 2)
          assert_equal(graph.nodes[1].adjacent[graph.nodes[2]], 3)
          assert_equal(graph.nodes[2].adjacent[graph.nodes[1]], 3)
  
        print('Success: test_graph_undirected')
  
  
  def main():
      test = TestGraph()
      test.test_graph()
keep keep keep keep replace keep keep keep keep keep
 Rework graph challenge and solution (#90) 
graphs_trees/graph/test_graph.py