     "mimetype": "text/x-python",
     "name": "python",
     "nbconvert_exporter": "python",
     "pygments_lexer": "ipython3",
     "version": "3.5.0"
    }
   },
   "nbformat": 4,
   "nbformat_minor": 0
  }
 
</s> remove     "        height = self._check_height(self.root)\n",
 </s> add     "        height = self._check_balance(self.root)\n", </s> remove     "        diff = abs(left_height-right_height)\n",
 </s> add     "        diff = abs(left_height - right_height)\n", </s> remove     "        right_height = self._check_height(node.right)\n",
 </s> add     "        right_height = self._check_balance(node.right)\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",
   "version": "3.4.3"
     "mimetype": "text/x-python",
     "name": "python",
     "nbconvert_exporter": "python",
     "pygments_lexer": "ipython3",
   "version": "3.4.3"
    }
   },
   "nbformat": 4,
   "nbformat_minor": 0
  }
keep keep keep keep replace keep keep keep keep keep
 Fix check balance challenge spacing 
graphs_trees/check_balance/check_balance_solution.ipynb