// calls.
type Switch struct {
	once sync.Once

	fmu   sync.RWMutex
	fltab map[FilterType]Filter

	smu   sync.RWMutex
	sotab Sockets
	stats stats
}

func (sw *Switch) init() {
	sw.fltab = make(map[FilterType]Filter)
	sw.sotab = make(Sockets)
	sw.stats = make(stats)
}

// Stats returns a list of per-cookie socket statistics.
func (sw *Switch) Stats() []Stat {
	var st []Stat

func (cfw *CoverageDataWriter) AppendSegment(args map[string]string, visitor CounterVisitor) error {
	cfw.stab = &stringtab.Writer{}
	cfw.stab.InitWriter()
	cfw.stab.Lookup("")

	var err error
	for k, v := range args {
		cfw.stab.Lookup(k)
		cfw.stab.Lookup(v)
	}

	ws := &slicewriter.WriteSeeker{}
	if err = cfw.writeSegmentPreamble(args, ws); err != nil {
		return err
	}

		return nil, fmt.Errorf("invalid empty package path")
	}
	x := &CoverageMetaDataBuilder{
		tmp: make([]byte, 0, 256),
		h:   md5.New(),
	}
	x.stab.InitWriter()
	x.stab.Lookup("")
	x.pkgpath = x.stab.Lookup(pkgpath)
	x.pkgname = x.stab.Lookup(pkgname)
	x.modpath = x.stab.Lookup(modulepath)
	io.WriteString(x.h, pkgpath)
	io.WriteString(x.h, pkgname)
	io.WriteString(x.h, modulepath)
	return x, nil
}

	if err = af.apply(so); err != nil {
		return err
	}

	sw.smu.Lock()
	defer sw.smu.Unlock()
	if so.Err != nil {
		sw.stats.getLocked(so.Cookie).CloseFailed++
		return so.Err
	}
	delete(sw.sotab, s)
	sw.stats.getLocked(so.Cookie).Closed++
	return nil
}

// Connect wraps syscall.Connect.
func (sw *Switch) Connect(s int, sa syscall.Sockaddr) (err error) {
	so := sw.sockso(s)
	if so == nil {

	if err = af.apply(so); err != nil {
		return err
	}

	sw.smu.Lock()
	defer sw.smu.Unlock()
	if so.Err != nil {
		sw.stats.getLocked(so.Cookie).CloseFailed++
		return so.Err
	}
	delete(sw.sotab, s)
	sw.stats.getLocked(so.Cookie).Closed++
	return nil
}

// Connect wraps [syscall.Connect].
func (sw *Switch) Connect(s syscall.Handle, sa syscall.Sockaddr) (err error) {
	so := sw.sockso(s)
	if so == nil {