if trace == nil {
		panic("nil trace")
	}
	old := ContextClientTrace(ctx)
	trace.compose(old)

	ctx = context.WithValue(ctx, clientEventContextKey{}, trace)
	if trace.hasNetHooks() {
		nt := &nettrace.Trace{
			ConnectStart: trace.ConnectStart,
			ConnectDone:  trace.ConnectDone,
		}
		if trace.DNSStart != nil {
			nt.DNSStart = func(name string) {