def attach_to_instance(self, instance, mountpoint):
        """
        Attaches this volume to the cloud server instance at the
        specified mountpoint. This requires a call to the cloud servers
        API; it cannot be done directly.
        """
        instance_id = _resolve_id(instance)
        try:
            resp = self._nova_volumes.create_server_volume(instance_id,
                    self.id, mountpoint)
        except Exception as e:
            raise exc.VolumeAttachmentFailed(e % "%s")
dataset/ETHPy150Open rackspace/pyrax/pyrax/cloudblockstorage.py/CloudBlockStorageVolume.attach_to_instance/swapped operands of `%`