      "        in_order_traversal(node, self.results.add_result)\n",
      "        assert_equal(str(self.results), \"[1, 2, 3, 5, 8]\")\n",
      "        self.results.clear_results()\n",
      "\n",
      "        pre_order_traversal(node, self.results.add_result)\n",
      "        assert_equal(str(self.results), \"[5, 2, 1, 3, 8]\")\n",
      "        self.results.clear_results()\n",
      "\n",
      "        post_order_traversal(node, self.results.add_result)\n",
      "        assert_equal(str(self.results), \"[1, 3, 2, 8, 5]\")\n",
 
</s> remove     "        pre_order_traversal(node, self.results.add_result)\n",
 </s> add     "        bst.pre_order_traversal(bst.root, self.results.add_result)\n", </s> remove     "        in_order_traversal(node, self.results.add_result)\n",
 </s> add     "        bst.in_order_traversal(bst.root, self.results.add_result)\n", </s> remove     "        in_order_traversal(node, self.results.add_result)\n",
 </s> add     "        bst.in_order_traversal(bst.root, self.results.add_result)\n", </s> remove     "        post_order_traversal(node, self.results.add_result)\n",
 </s> add     "        bst.post_order_traversal(bst.root, self.results.add_result)\n", </s> remove     "        post_order_traversal(node, self.results.add_result)\n",
 </s> add     "        bst.post_order_traversal(bst.root, self.results.add_result)\n",
    "        bst.pre_order_traversal(bst.root, self.results.add_result)\n",
      "        in_order_traversal(node, self.results.add_result)\n",
      "        assert_equal(str(self.results), \"[1, 2, 3, 5, 8]\")\n",
      "        self.results.clear_results()\n",
      "\n",
    "        bst.pre_order_traversal(bst.root, self.results.add_result)\n",
      "        assert_equal(str(self.results), \"[5, 2, 1, 3, 8]\")\n",
      "        self.results.clear_results()\n",
      "\n",
      "        post_order_traversal(node, self.results.add_result)\n",
      "        assert_equal(str(self.results), \"[1, 3, 2, 8, 5]\")\n",
keep keep keep keep replace keep keep keep keep keep
 Move tree dfs to a class 
graphs_trees/tree_dfs/dfs_challenge.ipynb