      }
     ],
     "source": [
      "%%writefile test_height.py\n",
      "from __future__ import print_function\n",
      "from nose.tools import assert_equal\n",
      "\n",
      "\n",
      "class TestHeight(object):\n",
      "\n",
 
</s> remove     "from __future__ import print_function\n",
 </s> add  </s> remove from __future__ import print_function
 </s> add  </s> remove     "    # TODO: Implement me"
 </s> add     "    # TODO: Implement me\n",
    "    pass"
      }
     ],
     "source": [
      "%%writefile test_height.py\n",

      "from nose.tools import assert_equal\n",
      "\n",
      "\n",
      "class TestHeight(object):\n",
      "\n",
keep keep keep keep replace keep keep keep keep keep
 Removed unused import statements, fixed compile error on skeleton challenge code. 
graphs_trees/tree_height/height_solution.ipynb