public KafkaCluster addBrokers(int count){
  if (running)   throw new IllegalStateException("Unable to add a broker when the cluster is already running");
  AtomicLong added=new AtomicLong();
  while (added.intValue() < count) {
    kafkaServers.computeIfAbsent(new Integer(added.intValue() + 1),null);
  }
  return this;
}

public KafkaCluster addBrokers ( int count ) { if ( running ) throw new IllegalStateException ( "Unable to add a broker when the cluster is already running" ) ; AtomicLong added = new AtomicLong ( ) ; while ( added . intValue ( ) < count ) { kafkaServers . computeIfAbsent ( new Integer ( added . intValue ( ) + 1 ) , null ) ; } return this ; }
add a number of new kafka broker to the cluster . the broker ids will be generated .
