public function getRequiredAssetsToOutput()
    {
        $required = $this->requiredAssetGroup->getAssetPointers();
        $assetPointers = array_filter($required, array('\Concrete\Core\Http\ResponseAssetGroup', 'filterProvidedAssets'));
        $assets = array();
        $al = AssetList::getInstance();
        foreach ($assetPointers as $ap) {
            $asset = $ap->getAsset();
            if ($asset instanceof Asset) {
                $assets[] = $asset;
            }
        }
        // also include any hard-passed $assets into the group. This is rare but it's used for handle-less
        // assets like layout css
        $assets = array_merge($this->requiredAssetGroup->getAssets(), $assets);

        return $assets;
    }