      "# %load test_add_digits.py\n",
      "from nose.tools import assert_equal, assert_raises\n",
      "\n",
      "\n",
      "class TestAddDigits(object):\n",
      "\n",
      "    def test_add_digits(self, func):\n",
      "        assert_raises(TypeError, func, None)\n",
      "        assert_raises(ValueError, func, -1)\n",
      "        assert_equal(func(0), 0)\n",
 
</s> remove     "class TestAddDigits(object):\n",
 </s> add     "class TestAddDigits(unittest.TestCase):\n", </s> remove     "        assert_raises(TypeError, func, None)\n",
    "        assert_raises(ValueError, func, -1)\n",
    "        assert_equal(func(0), 0)\n",
    "        assert_equal(func(9), 9)\n",
    "        assert_equal(func(138), 3)\n",
    "        assert_equal(func(65536), 7) \n",
 </s> add     "        self.assertRaises(TypeError, func, None)\n",
    "        self.assertRaises(ValueError, func, -1)\n",
    "        self.assertEqual(func(0), 0)\n",
    "        self.assertEqual(func(9), 9)\n",
    "        self.assertEqual(func(138), 3)\n",
    "        self.assertEqual(func(65536), 7) \n", </s> remove     "        assert_raises(TypeError, func, None)\n",
    "        assert_raises(ValueError, func, -1)\n",
    "        assert_equal(func(0), 0)\n",
    "        assert_equal(func(9), 9)\n",
    "        assert_equal(func(138), 3)\n",
    "        assert_equal(func(65536), 7) \n",
 </s> add     "        self.assertRaises(TypeError, func, None)\n",
    "        self.assertRaises(ValueError, func, -1)\n",
    "        self.assertEqual(func(0), 0)\n",
    "        self.assertEqual(func(9), 9)\n",
    "        self.assertEqual(func(138), 3)\n",
    "        self.assertEqual(func(65536), 7) \n", </s> remove     "from nose.tools import assert_equal, assert_raises\n",
 </s> add     "import unittest\n", </s> remove class TestAddDigits(object):
 </s> add class TestAddDigits(unittest.TestCase):
    "class TestAddDigits(unittest.TestCase):\n",
      "# %load test_add_digits.py\n",
      "from nose.tools import assert_equal, assert_raises\n",
      "\n",
      "\n",
    "class TestAddDigits(unittest.TestCase):\n",
      "\n",
      "    def test_add_digits(self, func):\n",
      "        assert_raises(TypeError, func, None)\n",
      "        assert_raises(ValueError, func, -1)\n",
      "        assert_equal(func(0), 0)\n",
keep keep keep keep replace keep keep keep keep keep
 #273: Remove nose dependency for math_probability/ (#281) 
math_probability/add_digits/add_digits_challenge.ipynb