public static function add_attribute() {
		ob_start();

		check_ajax_referer( 'add-attribute', 'security' );

		if ( ! current_user_can( 'edit_products' ) || ! isset( $_POST['taxonomy'], $_POST['i'] ) ) {
			wp_die( -1 );
		}

		$i             = absint( $_POST['i'] );
		$metabox_class = array();
		$attribute     = new WC_Product_Attribute();

		$attribute->set_id( wc_attribute_taxonomy_id_by_name( sanitize_text_field( wp_unslash( $_POST['taxonomy'] ) ) ) );
		$attribute->set_name( sanitize_text_field( wp_unslash( $_POST['taxonomy'] ) ) );
		$attribute->set_visible( apply_filters( 'woocommerce_attribute_default_visibility', 1 ) );
		$attribute->set_variation( apply_filters( 'woocommerce_attribute_default_is_variation', 0 ) );

		if ( $attribute->is_taxonomy() ) {
			$metabox_class[] = 'taxonomy';
			$metabox_class[] = $attribute->get_name();
		}

		include 'admin/meta-boxes/views/html-product-attribute.php';
		wp_die();
	}