public ZkMigrationLeadershipState withNewKRaftController(int controllerId, int controllerEpoch) {
        return new ZkMigrationLeadershipState(
            controllerId, controllerEpoch, this.kraftMetadataOffset,
            this.kraftMetadataEpoch, this.lastUpdatedTimeMs, this.migrationZkVersion, this.zkControllerEpoch, this.zkControllerEpochZkVersion);
    }
A Kafka-internal constant used to indicate that the znode version is unknown. See ZkVersion.UnknownVersion.
metadata/src/main/java/org/apache/kafka/metadata/migration/ZkMigrationLeadershipState.java