'Renders (thereby finalizing) the content of the response.
If the content has already been rendered, this is a no-op.
Returns the baked response instance.'

def render(self):

    retval = self
    if (not self._is_rendered):
        self.content = self.rendered_content
        for post_callback in self._post_render_callbacks:
            newretval = post_callback(retval)
            if (newretval is not None):
                retval = newretval
    return retval
