public function __construct($hostList, $timeout = null, $kafkaHostList = null)
{
if ($hostList instanceof \Kafka\ClusterMetaData) {
$metadata = $hostList;
} elseif ($kafkaHostList !== null) {
$metadata = new \Kafka\MetaDataFromKafka($kafkaHostList);
} else {
$metadata = new \Kafka\ZooKeeper($hostList, $timeout);
}
$this->client = new \Kafka\Client($metadata);
}