private static string ConvertUrlsToAbsolute(string baseUrl, string content)
        {
            if (string.IsNullOrWhiteSpace(content))
            {
                return(content);
            }
            var regex = new Regex("url\\((?<prefix>['\"]?)(?<url>[^)]+?)(?<suffix>['\"]?)\\)");

            return(regex.Replace(content, (Match match) => "url(" + CssRewriteUrlTransformFixed.RebaseUrlToAbsolute(baseUrl, match.Groups["url"].Value, match.Groups["prefix"].Value, match.Groups["suffix"].Value) + ")"));
        }
        public string Process(string includedVirtualPath, string input)
        {
            if (includedVirtualPath == null)
            {
                throw new ArgumentNullException("includedVirtualPath");
            }
            if (includedVirtualPath.Length < 1 || includedVirtualPath[0] != '~')
            {
                throw new ArgumentException("includedVirtualPath must be valid ( i.e. have a length and start with ~ )");
            }
            var directory = VirtualPathUtility.GetDirectory(includedVirtualPath);

            return(CssRewriteUrlTransformFixed.ConvertUrlsToAbsolute(directory, input));
        }