public void update(Cluster cluster, long now) {
        if (cluster.isBootstrapConfigured()) {
            log.debug("Setting bootstrap cluster metadata {}.", cluster);
            bootstrapCluster = cluster;
        } else {
            log.debug("Updating cluster metadata to {}", cluster);
            this.lastMetadataUpdateMs = now;
        }

        this.state = State.QUIESCENT;
        this.fatalException = null;

        if (!cluster.nodes().isEmpty()) {
            this.cluster = cluster;
        }
    }
Receive new metadata, and transition into the QUIESCENT state.
Updates lastMetadataUpdateMs, cluster, and authException.
clients/src/main/java/org/apache/kafka/clients/admin/internals/AdminMetadataManager.java