def _get_stream_for_parsing(self):
        cached_data = getattr(self, '_cached_data', None)
        if cached_data is not None:
            return BytesIO(cached_data)
        return self.stream
This is the same as accessing :attr:`stream` with the difference
dataset/ETHPy150Open Eforcers/gae-flask-todo/lib/werkzeug/wrappers.py/BaseRequest._get_stream_for_parsing