// NewPreflightPhase returns a new prefight phase. func NewPreflightPhase() workflow.Phase { … } func runPreflight(c workflow.RunData) error { … } // enforceVersionPolicies makes sure that the version the user specified is valid to upgrade to. // It handles both fatal and skippable (with --force) errors. func enforceVersionPolicies(newK8sVersionStr string, newK8sVersion *version.Version, allowExperimentalUpgrades, allowRCUpgrades, force bool, versionGetter upgrade.VersionGetter) error { … }