protected function createRequestObject($objectType)
    {
        $repository = $this->getRepository();

        switch ($objectType) {
            case 'SessionInput':
                $this->requestObject = new SessionInput();
                break;
            case 'ContentTypeGroupCreateStruct':
                $this->requestObject = $repository
                    ->getContentTypeService()
                    ->newContentTypeGroupCreateStruct('identifier');
                break;

            case 'ContentTypeGroupUpdateStruct':
                $this->requestObject = $repository
                    ->getContentTypeService()
                    ->newContentTypeGroupUpdateStruct();
                break;

            case 'ViewInput':
                $this->requestObject = new ViewInput();
                break;

            default:
                throw new InvalidArgumentException($objectType, 'type is not defined yet');
        }
    }