RestService :: getProviderList: Bitrix method

      
<?php 
//  Bitrix\Bizproc\RestService :: getProviderList()
//  /dist/bitrix/modules/bizproc/lib/restservice.php:1207

    public static function getProviderList($params, $n, $server)
    {
        if (Loader::includeModule('messageservice'))
        {
            return \Bitrix\MessageService\RestService::getSenderList($params, $n, $server);
        }

        if(!$server->getClientId())
        {
            throw new AccessException("Application context required");
        }

        self::checkAdminPermissions();
        $iterator = RestProviderTable::getList(array(
            'select' => array('CODE'),
            'filter' => array(
                '=APP_ID' => $server->getClientId()
            )
        ));

        $result = array();
        while ($row = $iterator->fetch())
        {
            $result[] = $row['CODE'];
        }
        return $result;
    }