protected function initializeProductSuperLink(array $attr)
    {

        // laod parent/product ID
        $parentId = $attr[MemberNames::PARENT_ID];
        $productId = $attr[MemberNames::PRODUCT_ID];

        // query whether or not the product super link already exists
        if ($this->loadProductSuperLink($productId, $parentId)) {
            return;
        }

        // simply return the attributes
        return $attr;
    }