code: @Override
  	public void open(FileInputSplit split) throws IOException {
  		super.open(split);
  		LOG.debug("Initialize Ethereum reader");
  		// temporary measure to set buffer size to 1, otherwise we cannot guarantee that checkpointing works
  		ebr = new EthereumBlockReader(this.stream,this.maxSizeEthereumBlock,1,this.useDirectBuffer);
  	}
docs: /*
  Reads data supplied by Flink with @see org.zuinnote.hadoop.ethereum.format.common.EthereumBlockReader
  
  (non-Javadoc)
  @see org.apache.flink.api.common.io.FileInputFormat#open(org.apache.flink.core.fs.FileInputSplit)