การแทรก node เข้าไปใน Binary Search Tree

class BinarySearchTree:
  def __init__(self):
    self.root = None

  def insert(self, data):
    new_node = TreeNode(data)
    # Check if the BST is empty
    if ____ == None:
      self.root = new_node
      return
    else:
      current_node = self.root
      while True:
        # Check if the data to insert is smaller than the current node's data
        if ____ < ____:
          if current_node.left_child == None:
            current_node.left_child = new_node
            return 
          else:
            current_node = current_node.left_child
        # Check if the data to insert is greater than the current node's data
        elif ____ > ____:
          if current_node.right_child == None:
            current_node.right_child = new_node
            return
          else:
            current_node = current_node.right_child

bst = CreateTree()
bst.insert("Pride and Prejudice")
print(search(bst, "Pride and Prejudice"))