code: private void recalculateWordsInUse() {
          // Traverse the bitset until a used word is found
          int i;
          for (i = wordsInUse-1; i >= 0; i--)
              if (words[i] != 0)
                  break;
  
          wordsInUse = i+1; // The new logical size
      }
docs: Sets the field wordsInUse to the logical size in words of the bit set.
  WARNING:This method assumes that the number of words actually in use is
  less than or equal to the current value of wordsInUse!