old_contents: class Address(object):
      def __init__(self, x, y, z, depth):
          self.x = x
          self.y = y
          self.z = z
          self.depth = depth
          
      def get_address_at_depth(depth):
          mask = 1 << depth
          x_bit = (mask & self.x) >> depth
          y_bit = (mask & self.y) >> depth
          z_bit = (mask & self.z) >> depth
          return (x, y, z)
  
  
  class Octree(object):
      def __init__(self, address, data):
          self.parent = None
          self.children = [
              [
                  [None, None],
                  [None, None]
              ],
              [
                  [None, None],
                  [None, None]
              ]
          ]
          self.address = address
          self.data = data
  
      def insert(self, node):
          pass
  
      def pop(self, address):
          pass
          
  
new_contents: class Address(object):
      def __init__(self, x, y, z, depth):
          self.x = x
          self.y = y
          self.z = z
          self.depth = depth
          
      def get_address_at_depth(self, depth):
          mask = 1 << depth
          x_bit = (mask & self.x) >> depth
          y_bit = (mask & self.y) >> depth
          z_bit = (mask & self.z) >> depth
          return (x, y, z)
          
      def is_parent_of(self, other):
          if other.depth > self.depth:
              pass
          else:
              return False
              
      def is_child_of(self, other):
          if other.depth < self.depth:
              pass
          else:
              return False
              
      def is_sibling_of(self, other):
          if other.depth == self.depth:
              pass
          else:
              return False
  
  
  class Octree(object):
      def __init__(self, address, data):
          self.parent = None
          self.children = [
              [
                  [None, None],
                  [None, None]
              ],
              [
                  [None, None],
                  [None, None]
              ]
          ]
          self.address = address
          self.data = data
  
      def insert(self, tree):
          pass
  
      def pop(self, address):
          pass
          
  
subject: Add skeletons to classes