docs: public DiskRange span(DiskRange otherDiskRange)
      {
          requireNonNull(otherDiskRange, "otherDiskRange is null");
          long start = Math.min(this.offset, otherDiskRange.getOffset());
          long end = Math.max(getEnd(), otherDiskRange.getEnd());
          return new DiskRange(start, toIntExact(end - start));
      }