// exist.
		gi = newGroupInfo(members)
	} else {
		gi.Members = set.CreateStringSet(append(gi.Members, members...)...).ToSlice()
		gi.UpdatedAt = UTCNow()
	}

	if err := store.saveGroupInfo(ctx, group, gi); err != nil {
		return updatedAt, err
	}

	cache.iamGroupsMap[group] = gi

	// update user-group membership map
	for _, member := range members {
		gset := cache.iamUserGroupMemberships[member]

// needed. No error if user(s) already are in the group.
func (sys *IAMSys) AddUsersToGroup(ctx context.Context, group string, members []string) (updatedAt time.Time, err error) {
	if !sys.Initialized() {
		return updatedAt, errServerNotInitialized
	}

	updatedAt, err = sys.store.AddUsersToGroup(ctx, group, members)
	if err != nil {
		return updatedAt, err
	}

	sys.notifyForGroup(ctx, group)
	return updatedAt, nil

	// yet set any policy
	uClient := s.getUserClient(c, accessKey, secretKey, "")
	c.mustNotListObjects(ctx, uClient, bucket)

	err = s.adm.UpdateGroupMembers(ctx, madmin.GroupAddRemove{
		Group:   "test-group",
		Members: []string{accessKey},
	})
	if err != nil {
		c.Fatalf("unable to add user to group: %v", err)
	}

	err = s.adm.SetPolicy(ctx, policy, "test-group", true)
	if err != nil {

		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrParseExpectedMember: {
		Code:           "ParseExpectedMember",
		Description:    "The SQL expression contains an unsupported use of MEMBER.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrParseUnsupportedSelect: {
		Code:           "ParseUnsupportedSelect",
		Description:    "The SQL expression contains an unsupported use of SELECT.",

		return
	}

	// Reject if the group add and remove are temporary credentials, or root credential.
	for _, member := range updReq.Members {
		ok, _, err := globalIAMSys.IsTempUser(member)
		if err != nil && err != errNoSuchUser {
			writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
			return
		}
		if ok {