test.SetForTest(t, &features.EnableAdditionalIpv4OutboundListenerForIpv6Only, true)
	cg := NewConfigGenTest(t, TestOptions{Services: testServices})
	proxy := cg.SetupProxy(&model.Proxy{IPAddresses: []string{"1111:2222::1"}})

	listeners := buildListeners(t, TestOptions{Services: testServices}, proxy)
	vo := xdstest.ExtractListener(model.VirtualOutboundListenerName, listeners)
	if vo == nil {

	"istio.io/istio/pkg/config/schema/collections"
	"istio.io/istio/pkg/test"
	"istio.io/istio/pkg/test/util/retry"
	"istio.io/istio/pkg/util/sets"
	"istio.io/istio/pkg/wellknown"
)

type TestOptions struct {
	// If provided, these configs will be used directly
	Configs        []config.Config
	ConfigPointers []*config.Config

	// If provided, the yaml string will be parsed and used as configs
	ConfigString string

			// Update MeshConfig
			m := mesh.DefaultMeshConfig()
			m.AccessLogFile = "foo"
			m.AccessLogEncoding = tc.encoding
			m.AccessLogFormat = tc.format
			listeners := buildListeners(t, TestOptions{MeshConfig: m}, nil)
			if len(listeners) != 2 {
				t.Errorf("expected to have 2 listeners, but got %v", len(listeners))
			}
			// Validate that access log filter uses the new format.
			for _, l := range listeners {

		DomainSuffix: "cluster.local",
	})
	defaultKubeClient.RunAndWait(stop)

	var gwc *gateway.Controller
	cg := core.NewConfigGenTest(t, core.TestOptions{
		Configs:             opts.Configs,
		ConfigString:        opts.ConfigString,
		ConfigTemplateInput: opts.ConfigTemplateInput,
		ConfigController:    configController,
		MeshConfig:          m,