public synchronized int requestUpdateForNewTopics() {
        // Override the timestamp of last refresh to let immediate update.
        this.lastRefreshMs = 0;
        this.needPartialUpdate = true;
        this.equivalentResponseCount = 0;
        this.requestVersion++;
        return this.updateVersion;
    }
Request an immediate update of the current cluster metadata info, because the caller is interested in
metadata that is being newly requested.
@return The current updateVersion before the update
clients/src/main/java/org/apache/kafka/clients/Metadata.java