private string Publish(GitHubClient client, IDictionary<string, string> content)
 {
   var response = client.Execute<GitHub.Gist>(new RestRequest("/gists", Method.POST) {  RequestFormat = DataFormat.Json }
     .AddBody(new GitHub.Gist { IsPublic = true, Files = content.ToDictionary(_ => _.Key, _ => new GistFile { Content = _.Value }) }));
   if ((response.ResponseStatus == ResponseStatus.Error) || !response.StatusCode.InRange(HttpStatusCode.OK, HttpStatusCode.Ambiguous - 1))
   {
     Logger.LogMessage("Gist error: {0}", response.ErrorMessage ?? string.Format("{0:D} {1}", response.StatusCode, response.StatusDescription));
     return null;
   }
   return response.Data != null ? response.Data.HtmlUrl : null;
 }