      "        \n",
      "        print('Success: test_find_loop_start')\n",
      "\n",
      "if __name__ == '__main__':\n",
      "    test = Test()\n",
      "    test.test_find_loop_start()"
     ]
    }
   ],
   "metadata": {
    "kernelspec": {
 
</s> remove     "class Test(object):\n",
 </s> add     "\n",
    "class TestFindLoopStart(object):\n",
    "    \n", </s> remove     "* Empty list\n",
    "* Not a circular linked list\n",
 </s> add     "* Empty list -> None\n",
    "* Not a circular linked list -> None\n",
    "    main()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Test: Empty list\n",
      "Test: Not a circular linked list: One element\n",
      "Test: Not a circular linked list: Two elements\n",
      "Test: Not a circular linked list: Three or more elements\n",
      "Test: General case: Circular linked list\n",
      "Success: test_find_loop_start\n"
     ]
    }
   ],
   "source": [
    "%run -i test_find_loop_start.py"
      "        \n",
      "        print('Success: test_find_loop_start')\n",
      "\n",
      "if __name__ == '__main__':\n",
    "    main()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Test: Empty list\n",
      "Test: Not a circular linked list: One element\n",
      "Test: Not a circular linked list: Two elements\n",
      "Test: Not a circular linked list: Three or more elements\n",
      "Test: General case: Circular linked list\n",
      "Success: test_find_loop_start\n"
     ]
    }
   ],
   "source": [
    "%run -i test_find_loop_start.py"
    "    main()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Test: Empty list\n",
      "Test: Not a circular linked list: One element\n",
      "Test: Not a circular linked list: Two elements\n",
      "Test: Not a circular linked list: Three or more elements\n",
      "Test: General case: Circular linked list\n",
      "Success: test_find_loop_start\n"
     ]
    }
   ],
   "source": [
    "%run -i test_find_loop_start.py"
     ]
    }
   ],
   "metadata": {
    "kernelspec": {
keep keep keep keep replace replace keep keep keep keep keep
 Added find loop start challenge. 
linked_lists/find_loop_start/find_loop_start_solution.ipynb