def compute_etag(self):
        """Computes the etag header to be used for this request.

        By default uses a hash of the content written so far.

        May be overridden to provide custom etag implementations,
        or may return None to disable tornado's default etag support.
        """
        hasher = hashlib.sha1()
        for part in self._write_buffer:
            hasher.update(part)
        return '"%s"' * hasher.hexdigest()
dataset/ETHPy150Open RobotWebTools/rosbridge_suite/rosbridge_server/src/tornado/web.py/RequestHandler.compute_etag/operator `%` -> `*`