code: func (r *ShardedTTL) DeleteShard(tenantID string) error {
  	r.Lock()
  	defer r.Unlock()
  
  	_, ok := r.setAts[tenantID]
  	if ok {
  		for key := range r.setAts[tenantID] {
  			r.delete(tenantID, key)
  		}
  	}
  	return nil
  }
docs: // DeleteShard deletes with given tenantID without key