       "name": "stdout",
       "output_type": "stream",
       "text": [
        "Empty input\n",
        "One element\n",
        "Two or more elements\n",
        "Success: test_insertion_sort\n"
       ]
      }
 
</s> remove     "    if len(data) < 2:\n",
 </s> add     "    if data is None or len(data) < 2:\n", </s> remove    "pygments_lexer": "ipython2",
   "version": "2.7.10"
 </s> add    "pygments_lexer": "ipython3",
   "version": "3.4.3" </s> remove    "pygments_lexer": "ipython2",
   "version": "2.7.10"
 </s> add    "pygments_lexer": "ipython3",
   "version": "3.4.3"
      "None input\n",
       "name": "stdout",
       "output_type": "stream",
       "text": [
      "None input\n",
        "Empty input\n",
        "One element\n",
        "Two or more elements\n",
        "Success: test_insertion_sort\n"
       ]
      }
keep keep add keep keep keep keep keep keep
 Add None input test case to insertion sort 
sorting_searching/insertion_sort/insertion_sort_solution.ipynb