totalObjectSize, err := objInfo.GetActualSize()
	if err != nil {
		return err
	}

	if rs == nil && opts.PartNumber > 0 {
		rs = partNumberToRangeSpec(objInfo, opts.PartNumber)
	}

	// For providing ranged content
	start, rangeLen, err = rs.GetOffsetLength(totalObjectSize)
	if err != nil {
		return err
	}

	// Set content length.
	w.Header().Set(xhttp.ContentLength, strconv.FormatInt(rangeLen, 10))