/**
         * Update system locked global setting.
         */
        internal static async Task UpdateSystemLockedGlobalSetting(AmazonDynamoDBClient dbClient,
                                                                   string loggedInUserId,
                                                                   bool value,
                                                                   bool force = false)
        {
            Debug.Untested();
            Debug.AssertValid(dbClient);
            Debug.AssertIDOrNull(loggedInUserId);

            // Setting 'system locked' flag.
            if (value)
            {
                // Setting to true (allowed)
                Debug.Tested();
                User loggedInUser = await IdentityServiceLogicLayer.FindUserByID(dbClient, loggedInUserId);

                Debug.AssertValidOrNull(loggedInUser);
                if (IdentityServiceLogicLayer.UserHasPermission(loggedInUser, IdentityServiceLogicLayer.PERMISSION_CAN_LOCK_SYSTEM))
                {
                    Debug.Tested();
                    //??--if (!IdentityGlobalSettings.ContainsKey(GLOBAL_SETTING_SYSTEM_LOCKED) || !(bool)IdentityGlobalSettings[GLOBAL_SETTING_SYSTEM_LOCKED])
                    bool systemLocked = await IdentityServiceLogicLayer.GetBoolIdentityGlobalSetting(dbClient, IdentityServiceLogicLayer.GLOBAL_SETTING_SYSTEM_LOCKED, false);

                    if (!systemLocked)
                    {
                        Debug.Tested();
                        //??--IdentityGlobalSettings[GLOBAL_SETTING_SYSTEM_LOCKED] = value;
                        await IdentityServiceDataLayer.AddIdentityGlobalSetting(dbClient, IdentityServiceLogicLayer.GLOBAL_SETTING_SYSTEM_LOCKED, value.ToString());
                    }
                    else
                    {
                        Debug.Tested();
                        throw new Exception(SharedLogicLayer.ERROR_SYSTEM_ALREADY_LOCKED);
                    }
                }
                else
                {
                    Debug.Tested();
                    throw new Exception(SharedLogicLayer.ERROR_NO_PERMISSION);
                }
            }
            else if (force)
            {
                // Forcing the set to false.
                Debug.Tested();
                //??--IdentityGlobalSettings[GLOBAL_SETTING_SYSTEM_LOCKED] = value;
                await IdentityServiceDataLayer.AddIdentityGlobalSetting(dbClient, IdentityServiceLogicLayer.GLOBAL_SETTING_SYSTEM_LOCKED, value.ToString());
            }
            else
            {
                // Setting to false (not allowed)
                Debug.Untested();
                throw new Exception(SharedLogicLayer.ERROR_NO_PERMISSION);
            }
        }
        /**
         * Update global setting.
         */
        internal static async Task UpdateIdentityGlobalSetting(AmazonDynamoDBClient dbClient, string loggedInUserId, string name, string value)
        {
            Debug.Untested();
            Debug.AssertValid(dbClient);
            Debug.AssertIDOrNull(loggedInUserId);
            Debug.AssertString(name);

            if (name == IdentityServiceLogicLayer.GLOBAL_SETTING_SYSTEM_LOCKED)
            {
                // Setting 'system locked' flag.
                Debug.Tested();
                await UpdateSystemLockedGlobalSetting(dbClient, loggedInUserId, bool.Parse(value), false);
            }
            else
            {
                // Not setting 'system locked' flag.
                Debug.Tested();
                await IdentityServiceDataLayer.AddIdentityGlobalSetting(dbClient, name, value);

                //??--IdentityGlobalSettings[name] = value;
            }
        }