public Optional<String> clusterId() {
        for (MetaProperties metaProps : logDirProps.values()) {
            if (metaProps.clusterId().isPresent()) {
                return metaProps.clusterId();
            }
        }
        return Optional.empty();
    }
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