old_contents: from __future__ import unicode_literals
  
  
  class Node(object):
      """A class for a binary search tree node."""
      def __init__(self, data):
          self.data = data
          self.left = None
          self.right = None
  
      def insert(self, val):
          """insert the value val into the BST.
  
          If val is already present, it will be ignored.
          """
          pass
  
      def contains(self, val):
          """return True if val is in the BST, False if not"""
          pass
  
      def size(self):
          """return the integer size of the BST.
  
          (equal to the total number of values stored in the tree),
          0 if the tree is empty.
          """
          pass
  
      def depth(self):
          """return an integer representing the total number of levels in the tree.
  
          If there is one value, the depth should be 1, if two values it'll be 2,
          if three values it may be 2 or three, depending, etc.
          """
          pass
  
      def balance(self):
          """return an integer, positive or negative represents how balanced the tree is.
  
          Trees which are higher on the left than the right should return a positive value,
          trees which are higher on the right than the left should return a negative value.
          An ideallyl-balanced tree should return 0.
          """
          pass
  
new_contents: from __future__ import unicode_literals
  
  
  class Node(object):
      """A class for a binary search tree node."""
      def __init__(self, val):
          self.val = val
          self.left = None
          self.right = None
  
      def insert(self, val):
          """insert a node with val into the BST.
  
          If val is already present, it will be ignored.
          """
          if self.contains(val):
              return
          
          pass
  
      def contains(self, val):
          """return True if val is in the BST, False if not"""
          pass
  
      def size(self):
          """return the integer size of the BST.
  
          (equal to the total number of values stored in the tree),
          0 if the tree is empty.
          """
          pass
  
      def depth(self):
          """return an integer representing the total number of levels in the tree.
  
          If there is one value, the depth should be 1, if two values it'll be 2,
          if three values it may be 2 or three, depending, etc.
          """
          pass
  
      def balance(self):
          """return an integer, positive or negative represents how balanced the tree is.
  
          Trees which are higher on the left than the right should return a positive value,
          trees which are higher on the right than the left should return a negative value.
          An ideallyl-balanced tree should return 0.
          """
          pass
  
subject: Change data to val