public static function add_product( $base_file ) {

		if ( ! is_readable( $base_file ) ) {
			return self::$instance;
		}
		$product = new Product( $base_file );

		Module_Factory::attach( $product, self::get_modules() );

		self::$products[ $product->get_slug() ] = $product;

		return self::$instance;
	}