docs: private static void insertionSortReverse(double[] keys, int[] vals, final int start, final int end) {
      // Classic insertion sort.
      for(int i = start + 1; i < end; i++) {
        for(int j = i; j > start; j--) {
          if(keys[j] <= keys[j - 1]) {
            break;
          }
          swap(keys, vals, j, j - 1);
        }
      }
    }