code: func (b *Backend) PurgeGroupMeta(groupUUID string) error {
  	_, ok := b.groups[groupUUID]
  	if !ok {
  		return NewErrGroupNotFound(groupUUID)
  	}
  
  	delete(b.groups, groupUUID)
  	return nil
  }
docs: // PurgeGroupMeta deletes stored group meta data