docs: private static void insertionSort(ModifiableDoubleDBIDList data, int start, int end, DoubleDBIDListIter iter1, DoubleDBIDListIter iter2) {
      for(int i = start + 1; i < end; i++) {
        for(int j = i; j > start; j--) {
          if(iter1.seek(j - 1).doubleValue() < iter2.seek(j).doubleValue()) {
            break;
          }
          data.swap(j, j - 1);
        }
      }
    }