r"""Render a template string using sandboxed environment.

        :param source: A string containing the page source.
        :param \*\*kwargs_context: The context associated with the page.
        :returns: The rendered template.

def render_template(self, source, **kwargs_context):
        r"""Render a template string using sandboxed environment.

        :param source: A string containing the page source.
        :param \*\*kwargs_context: The context associated with the page.
        :returns: The rendered template.
        """
        return self.jinja_env.from_string(source).render(kwargs_context)