def render(self, template, context_stack, delimiters=None):
        """
        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.

        """
        parsed_template = parse(template, delimiters)

        return parsed_template.render(self, context_stack)