Model/Catalog.php
public function loadProductById($productId)
    {
        $collection = $this->catalogCollection->create()
            ->addFieldToFilter('product_id', $productId)
            ->setPageSize(1);

        return $collection->getFirstItem();
    }
public function loadProductById($productId)
    {
        $collection = $this->catalogCollection->create()
            ->addFieldToFilter('product_id', $productId)
            ->setPageSize(1);

        return $collection->getFirstItem();
    }
public function loadProductById ( $ productId ) { $ collection = $ this -> catalogCollection -> create ( ) -> addFieldToFilter ( 'product_id' , $ productId ) -> setPageSize ( 1 ) ; return $ collection -> getFirstItem ( ) ; }
Load by product id.

@param int $productId

@return \Dotdigitalgroup\Email\Model\Catalog
Load by product id .