      "\n",
      "    def test_insertion_sort(self):\n",
      "        print('Empty input')\n",
      "        data = []\n",
      "        insertion_sort(data)\n",
      "        assert_equal(data, [])\n",
      "\n",
 
</s> remove     "    if len(data) < 2:\n",
 </s> add     "    if data is None or len(data) < 2:\n",
    "        print('None input')\n",
    "        data = None\n",
    "        insertion_sort(data)\n",
    "        assert_equal(data, None)\n",
    "\n",
      "\n",
      "    def test_insertion_sort(self):\n",
    "        print('None input')\n",
    "        data = None\n",
    "        insertion_sort(data)\n",
    "        assert_equal(data, None)\n",
    "\n",
      "        print('Empty input')\n",
      "        data = []\n",
      "        insertion_sort(data)\n",
      "        assert_equal(data, [])\n",
      "\n",
keep add keep keep keep keep keep
 Add None input test case to insertion sort 
sorting_searching/insertion_sort/insertion_sort_solution.ipynb