func objectPartIndexNums(parts []int, partNumber int) int {
	for i, part := range parts {
		if part != 0 && partNumber == part {
			return i
		}
	}
	return -1
}

// AddObjectPart - add a new object part in order.
func (fi *FileInfo) AddObjectPart(partNumber int, partETag string, partSize, actualSize int64, modTime time.Time, idx []byte, checksums map[string]string) {
	partInfo := ObjectPartInfo{
		Number:     partNumber,

			// Make sure to avoid writing to disks which we couldn't complete in erasure.Encode()
			onlineDisks[i] = nil
			continue
		}
		partsMetadata[i].Data = inlineBuffers[i].Bytes()
		partsMetadata[i].AddObjectPart(1, "", n, data.ActualSize(), modTime, index, nil)
	}

	// Fill all the necessary metadata.
	// Update `xl.meta` content on each disks.
	for index := range partsMetadata {
		partsMetadata[index].Size = n