      "    if start is end:\n",
      "        return True\n",
      "    queue = deque()\n",
      "    queue.append(start)\n",
      "    start.visited = True\n",
      "    while queue:\n",
      "        node = queue.popleft()\n",
      "        if node is None:\n",
      "            continue\n",
      "        if node is end:\n",
 
</s> remove     "    root.visited = True\n",
 </s> add     "    root.visit_state = State.visited\n", </s> remove     "            if not adj_node.visited:\n",
 </s> add     "            if adj_node.visit_state == State.unvisited:\n", </s> remove     "            if not adjacent_node.visited:\n",
 </s> add     "            if adjacent_node.visit_state == State.unvisited:\n", </s> remove     "    root.visited = True\n",
 </s> add     "    root.visit_state = State.visited\n", </s> remove     "                adj_node.visited = True\n",
 </s> add     "                adj_node.visit_state = State.visited\n",
    "    start.visit_state = State.visited\n",
      "    if start is end:\n",
      "        return True\n",
      "    queue = deque()\n",
      "    queue.append(start)\n",
    "    start.visit_state = State.visited\n",
      "    while queue:\n",
      "        node = queue.popleft()\n",
      "        if node is None:\n",
      "            continue\n",
      "        if node is end:\n",
keep keep keep keep replace keep keep keep keep keep
 Fixed issues with node state. 
graphs_trees/graph_path_exists/path_exists_solution.ipynb