def extract_device(self, object_file):
        match = self.extract_device_re.match(object_file)
        if match:
            return match.groups()[0]
        return "UNKNOWN"
Extract the device name from an object path.  Returns "UNKNOWN" if the
dataset/ETHPy150Open openstack/swift/swift/common/db_replicator.py/Replicator.extract_device