if err != nil {
		return nil, err
	}
	baseSet := EnvSet{compatibilityVersion: compatibilityVersion, newExpressions: base, storedExpressions: base}
	return baseSet.Extend(opts...)
}

func mustNewEnvSet(ver *version.Version, opts []VersionedOptions) *EnvSet {
	envSet, err := newEnvSet(ver, opts)
	if err != nil {
		panic(fmt.Sprintf("Default environment misconfigured: %v", err))
	}
	return envSet
}