code: private void insertionSort(int left, int right) {
          for (int p = left + 1; p <= right; p++) {
              byte[] tmpRange = ranges[p];
              String tmpFilename = filenames[p];
  
              int j;
              for (j = p; j > left && KeyUtils.compareKey(tmpRange, ranges[j - 1]) < 0; j--) {
                  ranges[j] = ranges[j - 1];
                  filenames[j] = filenames[j - 1];
              }
              ranges[j] = tmpRange;
              filenames[j] = tmpFilename;
          }
      }
docs: Internal insertion sort routine for subarrays of ranges that is used by quicksort.
  
  @param left
  the left-most index of the subarray.
  @param right
  the right-most index of the subarray.