public static function classForCurrentStep()
    {
        $step = self::getCurrentStep();
        if (!$step) {
            $step = 1;
        }
        if (Controller::has_curr()) {
            $requestStep = Controller::curr()->getRequest()->getVar('step');
            if ($requestStep) {
                $step = $requestStep;
            }
        }
        return str_replace(self::classNameNumber(), $step, get_called_class());
    }