Not able to use latest Kafka Consumer API

Days ago I was to get start with the newest Kafka document http://kafka.apache.org/documentation.html to learn about Kafka. But I meet some problem when I try to use the new Consumer API. I'd done the job with following steps:

1. Add a new dependency

<dependency>
    <groupId>org.apache.kafka</groupId>
    <artifactId>kafka-clients</artifactId>
    <version>0.8.2.1</version>
</dependency>

2. Add configurations

Latest documents did not contains such configurable things, it took me a while to figure out how KafkaProducer works, and I used some similar configurations to set the config map

    Map<String, Object> config = new HashMap<String, Object>();
    config.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,
            "host:9092");
    config.put(ConsumerConfig.GROUP_ID_CONFIG, "test");
    config.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG,
            StringDeserializer.class.getName());
    config.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG,
            StringDeserializer.class.getName());
    config.put(ConsumerConfig.PARTITION_ASSIGNMENT_STRATEGY, "range");

3. Use KafkaConsumer API

KafkaConsumer<String, String> consumer = new KafkaConsumer<String, String>(config);
consumer.subscribe("topic");

However, when I try to poll message from the broker, I got nothing but null:

Map<String, ConsumerRecords<String, String>> records = consumer.poll(0);
if (records != null)
    process(records);
else
    System.err.println("null");

And then I know what's wrong with the consumer after I checked the source code:

@Override
public Map<String, ConsumerRecords<K,V>> poll(long timeout) {
    // TODO Auto-generated method stub
    return null;
}

To make matters worse, I couldnot find any other useful information about the 0.8.2 API, since all usages about Kafka were not compatible with the latest version. I had to ask a question on SO, wishing to get some helpful advice.

Unfortunately, I could only get a bad news after ten days waiting:

--- @habsq ---
The new KafkaConsumer API will only be available in 0.8.3 cwiki.apache.org/confluence/display/KAFKA/Future+release+plan. Apparently there are some implementation in the trunk, although I have no clue about the state. For the time being I'm using the old consumer implementation.

Oops, documents could also lie, that's so sad (x﹏x)