public static function getDataApi()
 {
     $obj = new Mailjet();
     if (self::$data_api === null) {
         self::$data_api = mailjetdata::getInstance();
         self::$data_api->setKeys($obj->getAccountSettingsKey('API_KEY'), $obj->getAccountSettingsKey('SECRET_KEY'));
     }
     return self::$data_api;
 }