public void addTopicPartition(SystemStreamPartition ssp, long nextOffset) {
    LOG.info(String.format("Adding new topicPartition %s with offset %s to queue for consumer %s", ssp, nextOffset,
        this));
    topicPartitionToSSP.put(KafkaSystemConsumer.toTopicPartition(ssp), ssp); //registered SSPs

    // this is already vetted offset so there is no need to validate it
    nextOffsets.put(ssp, nextOffset);

    kafkaConsumerMetrics.setNumTopicPartitions(metricName, nextOffsets.size());
  }
Add new partition to the list of polled partitions.
Bust only be called before {@link KafkaConsumerProxy#start} is called..
@param ssp - SystemStreamPartition to add
@param nextOffset - add partition with this starting offset
samza-kafka/src/main/java/org/apache/samza/system/kafka/KafkaConsumerProxy.java