private static function fixLeftRightInURL($css) {
		$css = preg_replace(self::$patterns['left_in_url'], self::$patterns['tmpToken'], $css);
		$css = preg_replace(self::$patterns['right_in_url'], 'left', $css);
		$css = str_replace(self::$patterns['tmpToken'], 'right', $css);

		return $css;
	}