      "        invalid = Node(20)\n",
      "        bst.root.left = left\n",
      "        bst.root.right = right\n",
      "        bst.root.left.right = invalid\n",
      "        assert_equal(bst.validate(), False)\n",
      "\n",
      "        print('Success: test_bst_validate')\n",
      "\n",
      "\n",
      "def main():\n",
 
</s> remove     "        assert_equal(bst.validate(), False)\n",
 </s> add     "        self.assertEqual(bst.validate(), False)\n", </s> remove         assert_equal(bst.validate(), False)
 </s> add         self.assertEqual(bst.validate(), False) </s> remove     "        assert_equal(bst.validate(), True)\n",
 </s> add     "        self.assertEqual(bst.validate(), True)\n", </s> remove     "        assert_equal(bst.validate(), True)\n",
 </s> add     "        self.assertEqual(bst.validate(), True)\n", </s> remove         assert_equal(bst.validate(), True)
 </s> add         self.assertEqual(bst.validate(), True)
    "        self.assertEqual(bst.validate(), False)\n",
      "        invalid = Node(20)\n",
      "        bst.root.left = left\n",
      "        bst.root.right = right\n",
      "        bst.root.left.right = invalid\n",
    "        self.assertEqual(bst.validate(), False)\n",
      "\n",
      "        print('Success: test_bst_validate')\n",
      "\n",
      "\n",
      "def main():\n",
keep keep keep keep replace keep keep keep keep keep
 #273: Remove nose dependency for graphs_trees/ (#277) 
graphs_trees/bst_validate/bst_validate_challenge.ipynb