if root == nil {
							// We dont have usage information for this bucket in this
							// set, go to the next set
							continue
						}

						for id, usageInfo := range cache.flattenChildrens(*root) {
							prefix := decodeDirObject(strings.TrimPrefix(id, bucket+slashSeparator))
							// decodeDirObject to avoid any __XLDIR__ objects
							m[prefix] += uint64(usageInfo.Size)
						}
					}
				}

func (h dataUsageHash) String() string {
	return string(h)
}

// Key returns the key.
func (h dataUsageHash) Key() string {
	return string(h)
}

func (d *dataUsageCache) flattenChildrens(root dataUsageEntry) (m map[string]dataUsageEntry) {
	m = make(map[string]dataUsageEntry)
	for id := range root.Children {
		e := d.Cache[id]
		if len(e.Children) > 0 {
			e = d.flatten(e)
		}
		m[id] = e