if service.Spec.Type == api.ServiceTypeExternalName {
		return nil
	}

	// We don't want to auto-upgrade (add an IP) or downgrade (remove an IP)
	// PreferDualStack services following a cluster change to/from
	// dual-stackness.
	//
	// That means a PreferDualStack service will only be upgraded/downgraded
	// when:
	// - changing ipFamilyPolicy to "RequireDualStack" or "SingleStack" AND

	}

	// filter external ips, source ranges and ingress ips
	// prior to dual stack services, this was considered an error, but with dual stack
	// services, this is actually expected. Hence we downgraded from reporting by events
	// to just log lines with high verbosity
	ipFamilyMap := proxyutil.MapIPsByIPFamily(service.Spec.ExternalIPs)
	info.externalIPs = ipFamilyMap[ipFamily]

				// If this conflict was just one step in a longer chain of downgrades,
				// then we would want to keep going past it until we find a version
				// that doesn't have that problem. However, we only want to downgrade
				// away from an *existing* requirement if we can confirm that it actually
				// conflicts with mustSelect. (For example, we don't want
				// 'go get -u ./...' to incidentally downgrade some dependency whose

				revisionWarning = ""
			}
			if icpTag < tag {
				p.Printf("%s Istio is being upgraded from %s to %s.\n"+revisionWarning+check,
					warnMarker, icpTag, tag)
			} else {
				p.Printf("%s Istio is being downgraded from %s to %s.\n"+revisionWarning+check,
					warnMarker, icpTag, tag)
			}
		}
	}
	return nil
}

// GetTagVersion returns istio tag version
func GetTagVersion(tagInfo string) (string, error) {

				v := module.Version{Path: q.pattern}
				// The user has explicitly requested to downgrade their own module to
				// version "none". This is not an entirely unreasonable request: it
				// could plausibly mean “downgrade away everything that depends on any
				// explicit version of the main module”, or “downgrade away the
				// package with the same path as the main module, found in a module

  else
     # In case of a downgrade, a custom CoreDNS Corefile will be overwritten by a default Corefile. In that case,
     # the user will need to manually modify the resulting (default) Corefile after the downgrade is complete.
     echo "== Applying the latest default CoreDNS configuration =="

					},
					After: ClusterState{
						KubeVersion:    v1Y5.String(),
						KubeadmVersion: v1Y5.String(), // Note: The kubeadm version mustn't be "downgraded" here
						DNSVersion:     constants.CoreDNSVersion,
						EtcdVersion:    getEtcdVersion(v1Y5),
					},
				},
				{
					Description: "stable version",
					Before: ClusterState{

	// This may remove or downgrade modules in altMods.
	reqs := &mvsReqs{roots: keep}
	min, err := mvs.Req(mainModule, rootPaths, reqs)
	if err != nil {
		return nil, err
	}
	buildList, err := mvs.BuildList([]module.Version{mainModule}, reqs)
	if err != nil {
		return nil, err
	}

	// Check if modules in altMods were downgraded but not removed.

				if !ok {
					ckvs.Set(kv.Key, kv.Value)
				}
			}
			if _, ok := cp[subSys]; !ok {
				rnSubSys, ok := renamedSubsys[subSys]
				if !ok {
					// A config subsystem was removed or server was downgraded.
					continue
				}
				// Copy over settings from previous sub-system
				// to newly renamed sub-system
				for _, kv := range cp[rnSubSys][Default] {
					_, ok := c[subSys][tgt].Lookup(kv.Key)

				allErrs = append(allErrs, field.Invalid(field.NewPath("spec", "clusterIPs").Index(i), service.Spec.ClusterIPs, "may not change once set"))
			}
		}

	// something has been released (downgraded)
	case len(oldService.Spec.ClusterIPs) > len(service.Spec.ClusterIPs):
		// primary ClusterIP has been released
		if len(service.Spec.ClusterIPs) == 0 {