if call, ok := p.dialing[addr]; ok {
		// A dial is already in-flight. Don't start another.
		return call
	}
	call := &http2dialCall{p: p, done: make(chan struct{}), ctx: ctx}
	if p.dialing == nil {
		p.dialing = make(map[string]*http2dialCall)
	}
	p.dialing[addr] = call
	go call.dial(call.ctx, addr)
	return call
}

// run in its own goroutine.
func (c *http2dialCall) dial(ctx context.Context, addr string) {

		helpTestCreateUpdateDeleteWithFamilies(t, testCasesV4, []api.IPFamily{api.IPv4Protocol})
	})

	// Dual-stack v4,v6 cases: Covers the full matrix of:
	//    policy={nil, single, prefer, require}
	//    families={nil, single, dual}
	//    ips={nil, single, dual}
	testCasesV4V6 := []cudTestCase{{
		name: "policy:nil_families:nil_ips:nil",
		line: line(),
		create: svcTestCase{

	// SingleStack (single IPFamily). Services can be SingleStack (single IPFamily),
	// PreferDualStack (two dual-stack IPFamilies on dual-stack clusters or single
	// IPFamily on single-stack clusters), or RequireDualStack (two dual-stack IPFamilies
	// on dual-stack configured clusters, otherwise fail). The IPFamilies and ClusterIPs assigned

	// Defines which IP family to use for single stack or the order of IP families for dual-stack.
	// Valid list items are "IPv4", "IPv6".
	// More info: https://kubernetes.io/docs/concepts/services-networking/dual-stack/#services
	IpFamilies []string `protobuf:"bytes,29,rep,name=ipFamilies,proto3" json:"ipFamilies,omitempty"`

	IPFamilyPolicySingleStack IPFamilyPolicy = "SingleStack"
	// IPFamilyPolicyPreferDualStack indicates that this service prefers dual-stack when
	// the cluster is configured for dual-stack. If the cluster is not configured
	// for dual-stack the service will be assigned a single IPFamily. If the IPFamily is not
	// set in service.spec.ipFamilies then the service will be assigned the default IPFamily

	"ipFamilyPolicy":                "IPFamilyPolicy represents the dual-stack-ness requested or required by this Service. If there is no value provided, then this field will be set to SingleStack....

		}

		// if more than PodCIDR then
		// - validate for dual stack
		// - validate for duplication
		if len(node.Spec.PodCIDRs) > 1 {
			dualStack, err := netutils.IsDualStackCIDRStrings(node.Spec.PodCIDRs)
			if err != nil {
				allErrs = append(allErrs, field.InternalError(podCIDRsField, fmt.Errorf("invalid PodCIDRs. failed to check with dual stack with error:%v", err)))
			}

  //
  // This field may hold a maximum of two entries (dual-stack families, in
  // either order).  These families must correspond to the values of the
  // clusterIPs field, if specified. Both clusterIPs and ipFamilies are
  // governed by the ipFamilyPolicy field.
  // +listType=atomic
  // +optional
  repeated string ipFamilies = 19;

  // IPFamilyPolicy represents the dual-stack-ness requested or required by

- The `CloudDualStackNodeIPs` feature is now `beta`, meaning that when using
  an external cloud provider that has been updated to support the feature,
  you can pass comma-separated dual-stack `--node-ips` to `kubelet` and have
  the cloud provider take both IPs into account. ([#120275](https://github.com/kubernetes/kubernetes/pull/120275), [@danwinship](https://github.com/danwinship))

- Graduated HorizontalPodAutoscaler support for per-container metrics to stable. ([#123482](https://github.com/kubernetes/kubernetes/pull/123482), [@sanposhiho](https://github.com/sanposhiho))