code: public int getNextRangeIndex() {
          int length = rangeIndexList.size();
          if (length > 0) {
              Integer rindex = rangeIndexList.get(length - 1);
              return rindex.intValue();
          }
          return 0;
      }
docs: ************************************************************************
  getNextRangeIndex The range index for walkHash().
  ***********************************************************************