          root = Node(5)
          left = Node(5)
          right = Node(8)
          invalid = Node(20)
          root.left = left
          root.right = right
          root.left.right = invalid
          assert_equal(validate_bst(root), False)
  
          print('Success: test_bst_validate')
  
  
  def main():
 
</s> remove         node = Node(5)
        insert(node, 8)
        insert(node, 5)
        insert(node, 6)
        insert(node, 4)
        insert(node, 7)
        assert_equal(validate_bst(node), True)

        root = Node(5)
 </s> add         bst = BstValidate(Node(5))
        bst.insert(8)
        bst.insert(5)
        bst.insert(6)
        bst.insert(4)
        bst.insert(7)
        assert_equal(bst.validate(), True)

        bst = BstValidate(Node(5)) </s> remove     "        root.left = left\n",
    "        root.right = right\n",
    "        root.left.right = invalid\n",
    "        assert_equal(validate_bst(root), False)\n",
 </s> add     "        bst.root.left = left\n",
    "        bst.root.right = right\n",
    "        bst.root.left.right = invalid\n",
    "        assert_equal(bst.validate(), False)\n", </s> remove     "        root.left = left\n",
    "        root.right = right\n",
    "        root.left.right = invalid\n",
    "        assert_equal(validate_bst(root), False)\n",
 </s> add     "        bst.root.left = left\n",
    "        bst.root.right = right\n",
    "        bst.root.left.right = invalid\n",
    "        assert_equal(bst.validate(), False)\n", </s> remove     "        node = Node(5)\n",
    "        insert(node, 8)\n",
    "        insert(node, 5)\n",
    "        insert(node, 6)\n",
    "        insert(node, 4)\n",
    "        insert(node, 7)\n",
    "        assert_equal(validate_bst(node), True)\n",
    "\n",
    "        root = Node(5)\n",
 </s> add     "        bst = BstValidate(Node(5))\n",
    "        bst.insert(8)\n",
    "        bst.insert(5)\n",
    "        bst.insert(6)\n",
    "        bst.insert(4)\n",
    "        bst.insert(7)\n",
    "        assert_equal(bst.validate(), True)\n",
    "\n",
    "        bst = BstValidate(Node(5))\n", </s> remove     "        node = Node(5)\n",
    "        insert(node, 8)\n",
    "        insert(node, 5)\n",
    "        insert(node, 6)\n",
    "        insert(node, 4)\n",
    "        insert(node, 7)\n",
    "        assert_equal(validate_bst(node), True)\n",
    "\n",
    "        root = Node(5)\n",
 </s> add     "        bst = BstValidate(Node(5))\n",
    "        bst.insert(8)\n",
    "        bst.insert(5)\n",
    "        bst.insert(6)\n",
    "        bst.insert(4)\n",
    "        bst.insert(7)\n",
    "        assert_equal(bst.validate(), True)\n",
    "\n",
    "        bst = BstValidate(Node(5))\n",
        bst.root.left = left
        bst.root.right = right
        bst.root.left.right = invalid
        assert_equal(bst.validate(), False)
          root = Node(5)
          left = Node(5)
          right = Node(8)
          invalid = Node(20)
        bst.root.left = left
        bst.root.right = right
        bst.root.left.right = invalid
        assert_equal(bst.validate(), False)
        bst.root.left = left
        bst.root.right = right
        bst.root.left.right = invalid
        assert_equal(bst.validate(), False)
        bst.root.left = left
        bst.root.right = right
        bst.root.left.right = invalid
        assert_equal(bst.validate(), False)
        bst.root.left = left
        bst.root.right = right
        bst.root.left.right = invalid
        assert_equal(bst.validate(), False)
  
          print('Success: test_bst_validate')
  
  
  def main():
keep keep keep keep replace replace replace replace keep keep keep keep keep
 Move bst validate to a class (#98) 
graphs_trees/bst_validate/test_bst_validate.py