public boolean loggableChangeSinceState(ZkMigrationLeadershipState other) {
        if (other == null) {
            return false;
        }
        if (this.equals(other)) {
            return false;
        } else {
            // Did the controller change, or did we finish the migration?
            return
                this.kraftControllerId != other.kraftControllerId ||
                this.kraftControllerEpoch != other.kraftControllerEpoch ||
                (!other.initialZkMigrationComplete() && this.initialZkMigrationComplete());
        }
    }
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