code: @Override
  	public Tuple2<Long,Long> getCurrentState() throws IOException {
  		return new Tuple2<>(this.stream.getPos(), this.currentTransactionCounterInBlock);
  	}
docs: /*
  Saves the current state of the stream
  
  @return current position in stream
  
  (non-Javadoc)
  @see org.apache.flink.api.common.io.CheckpointableInputFormat#getCurrentState()