code: def HandleNetworkInterfaces(self, result):
      
      network_interfaces = self._ExtractInterfaceMetadata(result)
  
      if self.network_setup_enabled:
        self.network_setup.EnableNetworkInterfaces(
            [interface.name for interface in network_interfaces[1:]])
  
      for interface in network_interfaces:
        if self.ip_forwarding_enabled:
          self.ip_forwarding.HandleForwardedIps(
              interface.name, interface.forwarded_ips, interface.ip)
docs: Called when network interface metadata changes.
  
      Args:
        result: dict, the metadata response with the network interfaces.