def frames(self, request, tag):
        """
        Render the list of frames in this L{_StackElement}, replacing C{tag}.
        """
        return [
            _FrameElement(TagLoader(tag.clone()), frame)
            for frame
            in self.stackFrames]

        Render the list of frames in this L{_StackElement}, replacing C{tag}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/util.py