code: def render(self, template, context_stack, delimiters=None):
          
          parsed_template = parse(template, delimiters)
  
          return parsed_template.render(self, context_stack)
docs: Render a unicode template string, and return as unicode.
  
          Arguments:
  
            template: a template string of type unicode (but not a proper
              subclass of unicode).
  
            context_stack: a ContextStack instance.