this.mapper = new FieldNameBasedTupleToKafkaMapper<K,V>();
}
//for backward compatibility.
if(topicSelector == null) {
this.topicSelector = new DefaultTopicSelector((String) stormConf.get(TOPIC));
}
Map configMap = (Map) stormConf.get(KAFKA_BROKER_PROPERTIES);
Properties properties = new Properties();
properties.putAll(configMap);