public static function get_asset_url($file)
    {
        if (static::$manifest === null) {
            static::parse_manifest();
        }

        // There was no manifest or no file present.
        if (static::$manifest === null || !isset(static::$manifest[ $file ])) {
            return get_stylesheet_directory_uri() . '/public' . $file;
        }

        return get_stylesheet_directory_uri() . '/public' . static::$manifest[ $file ];
    }