Description
In kafka.consumer.javaapi.ZookeeperConsumerConnector.scala, the createMessageStreams() directly calls underlying.consume() (line 80)
In kafka.consumer.ZookeeperConsumerConnector.scala, the createMessageStreams() throws an exception if it has been called more than once (line 133).
The javaapi should throw if it is called more than once, just like the scala api.