     "mimetype": "text/x-python",
     "name": "python",
     "nbconvert_exporter": "python",
     "pygments_lexer": "ipython2",
     "version": "2.7.10"
    }
   },
   "nbformat": 4,
   "nbformat_minor": 0
  }
 
</s> remove    "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Success: test_foo\n"
     ]
    }
   ],
 </s> add    "outputs": [], </s> remove       "Overwriting test_foo.py\n"
 </s> add       "Overwriting test_group_ordered.py\n" </s> remove    "execution_count": 3,
 </s> add    "execution_count": 4, </s> remove     "%run -i test_foo.py"
 </s> add     "%run -i test_group_ordered.py"
   "version": "2.7.6"
     "mimetype": "text/x-python",
     "name": "python",
     "nbconvert_exporter": "python",
     "pygments_lexer": "ipython2",
   "version": "2.7.6"
    }
   },
   "nbformat": 4,
   "nbformat_minor": 0
  }
keep keep keep keep replace keep keep keep keep keep
 added both solutions w/ test 
arrays_strings/group_items/group_ordered_solution.ipynb