code: def postinit(self, left=None, right=None):
          
          self.left = left
          self.right = right
docs: Do some setup after initialisation.
  
          :param left: What is being applied to the operator on the left side.
          :type left: NodeNG or None
  
          :param right: What is being applied to the operator on the right side.
          :type right: NodeNG or None