     "execution_count": null,
     "metadata": {
      "collapsed": false
     },
     "outputs": [],
     "source": [
      "from random import randint\n",
      "\n",
      "def test_sort(num_items, stack=None):\n",
      "    if stack is None:\n",
 
</s> remove     "def test_sort(num_items, stack=None):\n",
    "    if stack is None:\n",
 </s> add     "class Test(object):\n",
    "    def get_sorted_stack(self, numbers):\n", </s> remove    "execution_count": null,
 </s> add    "execution_count": 3, </s> remove    "execution_count": null,
 </s> add    "execution_count": 2, </s> remove    "execution_count": null,
 </s> add    "execution_count": 1,
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Test: Empty stack\n",
      "Test: One element stack\n",
      "Test: Two or more element stack (general case)\n",
      "Success: test_sort_stack\n"
     ]
    }
   ],
     "execution_count": null,
     "metadata": {
      "collapsed": false
     },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Test: Empty stack\n",
      "Test: One element stack\n",
      "Test: Two or more element stack (general case)\n",
      "Success: test_sort_stack\n"
     ]
    }
   ],
     "source": [
      "from random import randint\n",
      "\n",
      "def test_sort(num_items, stack=None):\n",
      "    if stack is None:\n",
keep keep keep keep replace keep keep keep keep keep
 Reworked notebook: Added more detail to constraints and test cases.  Reworked unit test. 
stacks-queues/sort-stack.ipynb