public Optional<String> getZookeeperConnectString() {
        return brokerStarted ? Optional.of(zookeeper.getConnectString()) : Optional.empty();
    }
public Optional < String > getZookeeperConnectString ( ) { return brokerStarted ? Optional . of ( zookeeper . getConnectString ( ) ) : Optional . empty ( ) ; }
Get the current Zookeeper connection string

@return An Optional that will only contain a value if the broker is running