diff --git a/arrays-strings/hash-map.ipynb b/arrays-strings/hash-map.ipynb
index ada0f25..7a88504 100644
--- a/arrays-strings/hash-map.ipynb
+++ b/arrays-strings/hash-map.ipynb
@@ -17,7 +17,8 @@
     "* [Test Cases](#Test-Cases)\n",
     "* [Algorithm](#Algorithm)\n",
     "* [Code](#Code)\n",
-    "* [Pythonic-Code](#Pythonic-Code)"
+    "* [Pythonic-Code](#Pythonic-Code)\n",
+    "* [Unit Test](#Unit-Test)"
    ]
   },
   {
@@ -26,8 +27,14 @@
    "source": [
     "## Clarifying Questions\n",
     "\n",
-    "* Are the keys integers only?\n",
-    "    * Yes"
+    "*Problem statements are sometimes intentionally ambiguous.  Asking clarifying questions, identifying constraints, and stating assumptions help to ensure you code the intended solution.*\n",
+    "\n",
+    "* For simplicity, are the keys integers only?\n",
+    "    * Yes\n",
+    "* For collision resolution, can we use linked lists?\n",
+    "    * Yes\n",
+    "* Do we have to worry about load factors?\n",
+    "    * No"
    ]
   },
   {
@@ -36,6 +43,8 @@
    "source": [
     "## Test Cases\n",
     "\n",
+    "*Identifying and running through general and edge cases are important.  You generally will not be asked to write a unit test like what is shown below.*\n",
+    "\n",
     "* get on an empty hash table index\n",
     "* set on an empty hash table index\n",
     "* set on a non empty hash table index\n",
@@ -97,9 +106,9 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 1,
    "metadata": {
-    "collapsed": true
+    "collapsed": false
    },
    "outputs": [],
    "source": [
@@ -138,37 +147,76 @@
     "                del self.table[hash_index][i]"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Unit Test"
+   ]
+  },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 2,
    "metadata": {
     "collapsed": false
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Test: get on an empty hash table index\n",
+      "Test: set on an empty hash table index\n",
+      "Test: set on a non empty hash table index\n",
+      "Test: set on a key that already exists\n",
+      "Test: remove on a key that already exists\n",
+      "Test: remove on a key that doesn't exist\n",
+      "Success: test_end_to_end\n"
+     ]
+    }
+   ],
    "source": [
-    "table_size = 10\n",
-    "hash_table = HashTable(table_size)\n",
-    "print(\"get on an empty hash table index\")\n",
-    "print(hash_table.get(0))\n",
-    "print(\"set on an empty hash table index\")\n",
-    "hash_table.set(0, 'foo')\n",
-    "print(hash_table.get(0))\n",
-    "hash_table.set(1, 'bar')\n",
-    "print(hash_table.get(1))\n",
-    "print(\"set on a non empty hash table index\")\n",
-    "hash_table.set(10, 'foo2')\n",
-    "print(hash_table.get(0))\n",
-    "print(hash_table.get(10))\n",
-    "print(\"set on a key that already exists\")\n",
-    "hash_table.set(10, 'foo3')\n",
-    "print(hash_table.get(0))\n",
-    "print(hash_table.get(10))\n",
-    "print(\"remove on a key that already exists\")\n",
-    "hash_table.remove(10)\n",
-    "print(hash_table.get(0))\n",
-    "print(hash_table.get(10))\n",
-    "print(\"remove on a key that doesn't exist\")\n",
-    "hash_table.remove(-1)"
+    "from nose.tools import assert_equal\n",
+    "\n",
+    "class Test(object):\n",
+    "    \n",
+    "    # TODO: It would be better if we had unit tests for each\n",
+    "    # HashTable method in addition to the following end-to-end test\n",
+    "    def test_end_to_end(self):\n",
+    "        hash_table = HashTable(10)\n",
+    "        \n",
+    "        print(\"Test: get on an empty hash table index\")\n",
+    "        assert_equal(hash_table.get(0), None)\n",
+    "        \n",
+    "        print(\"Test: set on an empty hash table index\")\n",
+    "        hash_table.set(0, 'foo')\n",
+    "        assert_equal(hash_table.get(0), 'foo')\n",
+    "        hash_table.set(1, 'bar')\n",
+    "        assert_equal(hash_table.get(1), 'bar')\n",
+    "        \n",
+    "        print(\"Test: set on a non empty hash table index\")\n",
+    "        hash_table.set(10, 'foo2')\n",
+    "        assert_equal(hash_table.get(0), 'foo')\n",
+    "        assert_equal(hash_table.get(10), 'foo2')\n",
+    "        \n",
+    "        print(\"Test: set on a key that already exists\")\n",
+    "        hash_table.set(10, 'foo3')\n",
+    "        assert_equal(hash_table.get(0), 'foo')\n",
+    "        assert_equal(hash_table.get(10), 'foo3')\n",
+    "        \n",
+    "        print(\"Test: remove on a key that already exists\")\n",
+    "        hash_table.remove(10)\n",
+    "        assert_equal(hash_table.get(0), 'foo')\n",
+    "        assert_equal(hash_table.get(10), None)\n",
+    "        \n",
+    "        print(\"Test: remove on a key that doesn't exist\")\n",
+    "        hash_table.remove(-1)\n",
+    "        \n",
+    "        print('Success: test_end_to_end')\n",
+    "\n",
+    "if __name__ == '__main__':\n",
+    "    test = Test()\n",
+    "    test.test_end_to_end()"
    ]
   }
  ],