tierFVID     = "tier-free-versionID"
	tierFVMarker = "tier-free-marker"
	tierSkipFVID = "tier-skip-fvid"
)

// SetTierFreeVersionID sets free-version's versionID. This method is used by
// object layer to pass down a versionID to set for a free-version that may be
// created.
func (fi *FileInfo) SetTierFreeVersionID(versionID string) {
	if fi.Metadata == nil {
		fi.Metadata = make(map[string]string)
	}