code: @Override
  	public void reopen(FileInputSplit split, Tuple2<Long,Long> state) throws IOException {
  		try {
  			this.open(split);
  		} finally {
  			this.stream.seek(state.f0);
  			this.currentTransactionCounterInBlock=state.f1;
  		}
  	}
docs: /*
  Reopens the stream at a specific previously stored position and initializes the BitcoinBlockReader
  
  @param split FileInputSplit
  @param state position in the stream
  
  (non-Javadoc)
  @see org.apache.flink.api.common.io.CheckpointableInputFormat#reopen(org.apache.flink.core.io.InputSplit, java.io.Serializable)