      "    * Yes\n",
      "* If this is called on a None input, should we return False?\n",
      "    * Yes\n",
      "* Can we assume we already have a Node class with an insert method?\n",
      "    * Yes"
     ]
    },
    {
 
</s> remove     "    balanced, _, _ = __check_balance__(root)\n",
 </s> add     "    if root is None:\n",
    "        return False\n",
    "    balanced, _, _ = _check_balance(root)\n",
    "    * Yes\n",
    "* Can we assume this fits memory?\n",
      "    * Yes\n",
      "* If this is called on a None input, should we return False?\n",
      "    * Yes\n",
      "* Can we assume we already have a Node class with an insert method?\n",
    "    * Yes\n",
    "* Can we assume this fits memory?\n",
      "    * Yes"
     ]
    },
    {
keep keep keep add keep keep keep keep
 Polish check tree balance challenge and solution (#80)

Update constraints, test cases, tests, and code. 
graphs_trees/check_balance/check_balance_solution.ipynb