code: func getV6Network(config *networkConfiguration, i *bridgeInterface) *net.IPNet {
  	if config.AddressIPv6 != nil {
  		return config.AddressIPv6
  	}
  	if i.bridgeIPv6 != nil && i.bridgeIPv6.IP != nil && !i.bridgeIPv6.IP.IsLinkLocalUnicast() {
  		return i.bridgeIPv6
  	}
  
  	return nil
  }
docs: // Returns the non link-local IPv6 subnet for the containers attached to this bridge if found, nil otherwise