docs: @SuppressWarnings("WeakerAccess")
      public static void reverse(int[] order, int offset, int length) {
          for (int i = 0; i < length / 2; i++) {
              int t = order[offset + i];
              order[offset + i] = order[offset + length - i - 1];
              order[offset + length - i - 1] = t;
          }
      }