presto-parquet/src/main/java/io/prestosql/parquet/DiskRange.java/DiskRange/span
class DiskRange:    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));
    }