code: func (daemon *Daemon) DeleteNetwork(networkID string) error {
  	n, err := daemon.GetNetworkByID(networkID)
  	if err != nil {
  		return errors.Wrap(err, "could not find network by ID")
  	}
  	return daemon.deleteNetwork(n, false)
  }
docs: // DeleteNetwork destroys a network unless it's one of docker's predefined networks.