@Override
    public int hashCode() {
        return Objects.hash(emptyLogDirs,
            errorLogDirs,
            logDirProps,
            metadataLogDir);
    }
Find the cluster ID of this meta.properties ensemble.

@return  The cluster ID, or Optional.empty if none could be found.
metadata/src/main/java/org/apache/kafka/metadata/properties/MetaPropertiesEnsemble.java