new_contents: # -*- coding: utf-8 -*-
  
  from jinja2 import Environment, StrictUndefined
  
  
  class StrictEnvironment(Environment):
      """Jinja2 environment that raises an error when it hits a variable
      which is not defined in the context used to render a template.
      """
      def __init__(self, **kwargs):
          super(StrictEnvironment, self).__init__(
              undefined=StrictUndefined,
              **kwargs
          )
  
subject: Implement a strict subclass of jinja2 Environment