@Override
  public void initialize(InitializationInput initializationInput) {
    Validate.notNull(listener, "There is no listener set for the processor.");
    initSeqNumber = initializationInput.getExtendedSequenceNumber();
    shardId = initializationInput.getShardId();
    LOG.info("Initialization done for {} with sequence {}", this,
        initializationInput.getExtendedSequenceNumber().getSequenceNumber());
  }
Invoked by the Amazon Kinesis Client Library before data records are delivered to the RecordProcessor instance
(via processRecords).

@param initializationInput Provides information related to initialization
samza-aws/src/main/java/org/apache/samza/system/kinesis/consumer/KinesisRecordProcessor.java