/**
  * Add only is in stock products filter to product collection
  *
  * @param \Magento\Catalog\Model\ResourceModel\Product\Collection $collection
  * @return void
  */
 public function addIsInStockFilterToCollection($collection)
 {
     $stockFlag = 'has_stock_status_filter';
     if (!$collection->hasFlag($stockFlag)) {
         $isShowOutOfStock = $this->scopeConfig->getValue(\Magento\CatalogInventory\Model\Configuration::XML_PATH_SHOW_OUT_OF_STOCK, \Magento\Store\Model\ScopeInterface::SCOPE_STORE);
         $resource = $this->getStockStatusResource();
         $resource->addStockDataToCollection($collection, !$isShowOutOfStock);
         $collection->setFlag($stockFlag, true);
     }
 }