private static function buildLinksTags() :string {
		// this is where formatted links tags go
		$links = [];
		// pack and minify
		self::packAndMinifyLinks();
		// for each available link
		foreach(self::$_links as $href => $attributes) {
			// sort the attributes (compulse order needs)
			ksort($attributes);
			// build as base stylesheet link and merge its attributes
			$links[] = new \Polyfony\Element('link', $attributes);
		}
		return implode('', $links);
	}