func (sys *IAMSys) getStoredLDAPPolicyMappingKeys(ctx context.Context, isGroup bool) set.StringSet {
	entityKeysInStorage := set.NewStringSet()
	if iamOS, ok := sys.store.IAMStorageAPI.(*IAMObjectStore); ok {
		// Load existing mapping keys from the cached listing for
		// `IAMObjectStore`.
		iamFilesListing := iamOS.cachedIAMListing.Load().(map[string][]string)
		listKey := policyDBSTSUsersListKey
		if isGroup {
			listKey = policyDBGroupsListKey