      "            return 0\n",
      "        left_height = self._check_height(node.left)\n",
      "        if left_height == -1:\n",
      "            return -1\n",
      "        right_height = self._check_height(node.right)\n",
      "        if right_height == -1:\n",
      "            return -1\n",
      "        diff = abs(left_height-right_height)\n",
      "        if diff > 1:\n",
      "            return -1\n",
 
</s> remove     "        diff = abs(left_height-right_height)\n",
 </s> add     "        diff = abs(left_height - right_height)\n", </s> remove     "        left_height = self._check_height(node.left)\n",
 </s> add     "        left_height = self._check_balance(node.left)\n", </s> remove     "    def _check_height(self, node):\n",
 </s> add     "    def _check_balance(self, node):\n", </s> remove     "        height = self._check_height(self.root)\n",
 </s> add     "        height = self._check_balance(self.root)\n", </s> remove    "version": "3.5.0"
 </s> add    "version": "3.4.3"
    "        right_height = self._check_balance(node.right)\n",
      "            return 0\n",
      "        left_height = self._check_height(node.left)\n",
      "        if left_height == -1:\n",
      "            return -1\n",
    "        right_height = self._check_balance(node.right)\n",
      "        if right_height == -1:\n",
      "            return -1\n",
      "        diff = abs(left_height-right_height)\n",
      "        if diff > 1:\n",
      "            return -1\n",
keep keep keep keep replace keep keep keep keep keep
 Fix check balance challenge spacing 
graphs_trees/check_balance/check_balance_solution.ipynb