code: final protected synchronized void set(boolean verifyChecksum,
        Checksum sum, int maxChunkSize, int checksumSize ) {
      this.verifyChecksum = verifyChecksum;
      this.sum = sum;
      this.buf = new byte[maxChunkSize];
      this.checksum = new byte[checksumSize];
      this.count = 0;
      this.pos = 0;
    }
docs: Set the checksum related parameters
  @param verifyChecksum whether to verify checksum
  @param sum which type of checksum to use
  @param maxChunkSize maximun chunk size
  @param checksumSize checksum size