code: public byte checksum() {
      if(DEBUG_LEV > 10 )
        System.err.println("CRC8::checksum : Begin");
      //add 8 to the count,
      //call update with a byte constructed to add no more.
      //byte[] fake = {0};
      workingCRC8Count += 8;
      byte val = updateCRC8(fake, 0, 1);
      if(DEBUG_LEV > 10 )
        System.err.println("CRC8::checksum : End");
      return val;
    }
docs: Finalize the checksum, and return the value. After this is called, you
  must call reset() before attempting a new checksum.
  @return finalized checksum.