func (a byCreated) Less(i, j int) bool { return a[i].createTime.After(a[j].createTime) }

// Newest first.
type sandboxByCreated []sandboxGCInfo

func (a sandboxByCreated) Len() int           { return len(a) }
func (a sandboxByCreated) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
func (a sandboxByCreated) Less(i, j int) bool { return a[i].createTime.After(a[j].createTime) }