https://github.com/magento/magento2/blob/2.0.0/lib/internal/Magento/Framework/View/TemplateEngine/Xhtml/ResultFactory.php#L39
The code above can be shortened:
$instanceName = ResultInterface::class
See: PHP 5.5 class name resolution via ::class
https://github.com/magento/magento2/issues/2794