code: func (cgroup *CgroupResource) SetCreatedAt(createdAt time.Time) {
  	if createdAt.IsZero() {
  		return
  	}
  	cgroup.lock.Lock()
  	defer cgroup.lock.Unlock()
  
  	cgroup.createdAt = createdAt
  }
docs: // SetCreatedAt sets the timestamp for resource's creation time