variablesType.Fields = make(map[string]*apiservercel.DeclField)
	envSet, err := environment.MustBaseEnvSet(environment.DefaultCompatibilityVersion(), true).Extend(
		environment.VersionedOptions{
			IntroducedVersion: version.MajorMinor(1, 28),
			EnvOptions: []cel.EnvOption{
				cel.Variable("variables", variablesType.CelType()),
			},
			DeclTypes: []*apiservercel.DeclType{
				variablesType,
			},
		})
	if err != nil {

	buildEnvSet := func(envOpts []cel.EnvOption, declTypes []*apiservercel.DeclType) *environment.EnvSet {
		env, err := baseEnv.Extend(environment.VersionedOptions{
			IntroducedVersion: version.MajorMinor(1, 0),
			EnvOptions:        envOpts,
			DeclTypes:         declTypes,
		})
		if err != nil {
			panic(fmt.Sprintf("environment misconfigured: %v", err))
		}
		return env
	}

	extended, err := baseEnv.Extend(
		environment.VersionedOptions{
			// we record this as 1.0 since it was available in the
			// first version that supported this feature
			IntroducedVersion: version.MajorMinor(1, 0),
			EnvOptions: []cel.EnvOption{
				cel.Variable(subjectAccessReviewRequestVarName, subjectAccessReviewSpecRequestType.CelType()),
			},
			DeclTypes: []*apiservercel.DeclType{

	envSet, err := baseEnvSet.Extend(environment.VersionedOptions{
		// set to 1.0 because composition is one of the fundamental components
		IntroducedVersion: version.MajorMinor(1, 0),
		EnvOptions: []cel.EnvOption{
			cel.Variable("variables", declType.CelType()),
		},
		DeclTypes: []*apiservercel.DeclType{
			declType,
		},
	})
	if err != nil {
		return nil, err
	}