      "\n",
      "    def __init__(self, id):\n",
      "        self.id = id\n",
      "        self.visit_state = State.unvisited\n",
      "        self.adjacent = OrderedDict()  # key = node, val = weight\n",
      "\n",
      "    def __str__(self):\n",
      "        return str(self.id)\n",
      "\n",
      "\n",
 
</s> remove     "        self.adjacent = OrderedDict()  # key = node, val = weight\n",
 </s> add     "        self.adjacent = {}  # key = node, val = weight\n", </s> remove     "from collections import OrderedDict\n",
    "\n",
    "\n",
 </s> add  </s> remove         self.adjacent = OrderedDict()  # key = node, val = weight
 </s> add         self.adjacent = {}  # key = node, val = weight </s> remove     "        self.nodes = OrderedDict()  # key = node id, val = node\n",
 </s> add     "        self.nodes = {}  # key = node id, val = node\n",
    "        self.adjacent = {}  # key = node, val = weight\n",
      "\n",
      "    def __init__(self, id):\n",
      "        self.id = id\n",
      "        self.visit_state = State.unvisited\n",
    "        self.adjacent = {}  # key = node, val = weight\n",
      "\n",
      "    def __str__(self):\n",
      "        return str(self.id)\n",
      "\n",
      "\n",
keep keep keep keep replace keep keep keep keep keep
 Rework graph challenge and solution (#86) 
graphs_trees/graph/graph_solution.ipynb