fi.Parts[i] = partInfo
			return
		}
	}

	// Proceed to include new part info.
	fi.Parts = append(fi.Parts, partInfo)

	// Parts in FileInfo should be in sorted order by part number.
	sort.Slice(fi.Parts, func(i, j int) bool { return fi.Parts[i].Number < fi.Parts[j].Number })
}

// ObjectToPartOffset - translate offset of an object to offset of its individual part.