return fmt.Errorf("Error switching to ns fd %v: %v", n.Fd(), err)
	}
	return nil
}

// inspired by netns.Do() but with an existing fd.
func NetnsDo(fdable NetnsFd, toRun func() error) error {
	containedCall := func() error {
		threadNS, err := netns.GetCurrentNS()
		if err != nil {
			return fmt.Errorf("failed to open current netns: %v", err)
		}
		defer threadNS.Close()

}

func OpenNetns(nspath string) (NetnsCloser, error) {
	return nil, errors.New("not implemented")
}

// inspired by netns.Do() but with an existing fd.
func NetnsDo(fdable NetnsFd, toRun func() error) error {
	return errors.New("not implemented")

	"istio.io/istio/tools/istio-iptables/pkg/cmd"
	"istio.io/istio/tools/istio-iptables/pkg/dependencies"
)

type mockNetNs struct {
	path string
}

func (ns *mockNetNs) Do(toRun func(ns.NetNS) error) error {
	return toRun(ns)
}

func (*mockNetNs) Set() error {
	return nil
}

func (ns *mockNetNs) Path() string {
	return ns.path
}

func (*mockNetNs) Fd() uintptr {
	return 0
}

	ztunnelServer := &fakeZtunnel{}

	netServer := newNetServer(ztunnelServer, podNsMap, iptablesConfigurator, NewPodNetnsProcFinder(fakeFs()))

	netServer.netnsRunner = func(fdable NetnsFd, toRun func() error) error {
		return toRun()
	}
	netServer.Start(ctx)
	return netTestFixture{
		netServer:            netServer,
		podNsMap:             podNsMap,
		ztunnelServer:        ztunnelServer,

	ztunnelServer      ZtunnelServer
	currentPodSnapshot *podNetnsCache
	podIptables        *iptables.IptablesConfigurator
	podNs              PodNetnsFinder
	// allow overriding for tests
	netnsRunner func(fdable NetnsFd, toRun func() error) error
}

var _ MeshDataplane = &NetServer{}

func newNetServer(ztunnelServer ZtunnelServer, podNsMap *podNetnsCache, podIptables *iptables.IptablesConfigurator, podNs PodNetnsFinder) *NetServer {