      "def main():\n",
      "    test = TestUniqueChars()\n",
      "    test.test_unique_chars(unique_chars)\n",
      "    try:\n",
      "        test.test_unique_chars(unique_chars_hash)\n",
      "        test.test_unique_chars(unique_chars_inplace)\n",
      "    except NameError:\n",
      "        # Alternate solutions are only defined\n",
      "        # in the solutions file\n",
      "        pass\n",
      "\n",
 
</s> remove     "        test.test_unique_chars(unique_chars_hash)\n",
    "        test.test_unique_chars(unique_chars_inplace)\n",
 </s> add     "        unique_chars_set = UniqueCharsSet()\n",
    "        test.test_unique_chars(unique_chars_set.has_unique_chars)\n",
    "        unique_chars_in_place = UniqueCharsInPlace()\n",
    "        test.test_unique_chars(unique_chars_in_place.has_unique_chars)\n", </s> remove     "    test.test_unique_chars(unique_chars)\n",
 </s> add     "    unique_chars = UniqueChars()\n",
    "    test.test_unique_chars(unique_chars.has_unique_chars)\n", </s> remove     "    test.test_unique_chars(unique_chars)\n",
 </s> add     "    unique_chars = UniqueChars()\n",
    "    test.test_unique_chars(unique_chars.has_unique_chars)\n", </s> remove     "def unique_chars_hash(string):\n",
    "    if string is None:\n",
    "        return False\n",
    "    chars_set = set()\n",
    "    for char in string:\n",
    "        if char in chars_set:\n",
 </s> add     "class UniqueChars(object):\n",
    "\n",
    "    def has_unique_chars(self, string):\n",
    "        if string is None:\n", </s> remove     "        else:\n",
    "            chars_set.add(char)\n",
    "    return True"
 </s> add     "        chars_set = set()\n",
    "        for char in string:\n",
    "            if char in chars_set:\n",
    "                return False\n",
    "            else:\n",
    "                chars_set.add(char)\n",
    "        return True"
    "        unique_chars_set = UniqueCharsSet()\n",
    "        test.test_unique_chars(unique_chars_set.has_unique_chars)\n",
    "        unique_chars_in_place = UniqueCharsInPlace()\n",
    "        test.test_unique_chars(unique_chars_in_place.has_unique_chars)\n",
      "def main():\n",
      "    test = TestUniqueChars()\n",
      "    test.test_unique_chars(unique_chars)\n",
      "    try:\n",
    "        unique_chars_set = UniqueCharsSet()\n",
    "        test.test_unique_chars(unique_chars_set.has_unique_chars)\n",
    "        unique_chars_in_place = UniqueCharsInPlace()\n",
    "        test.test_unique_chars(unique_chars_in_place.has_unique_chars)\n",
    "        unique_chars_set = UniqueCharsSet()\n",
    "        test.test_unique_chars(unique_chars_set.has_unique_chars)\n",
    "        unique_chars_in_place = UniqueCharsInPlace()\n",
    "        test.test_unique_chars(unique_chars_in_place.has_unique_chars)\n",
      "    except NameError:\n",
      "        # Alternate solutions are only defined\n",
      "        # in the solutions file\n",
      "        pass\n",
      "\n",
keep keep keep keep replace replace keep keep keep keep keep
 Move unique chars to a class 
arrays_strings/unique_chars/unique_chars_challenge.ipynb