public static Uri AddParam(this Uri uri, string name, params string[] values) { UriBuilder builder = new UriBuilder(uri); ICollection <Tuple <string, string> > paramlist = RestUrl.SplitParams(builder.Query).ToList(); foreach (string value in values) { paramlist.Add(new Tuple <string, string>(name, value)); } builder.Query = RestUrl.JoinParams(paramlist); return(builder.Uri); }