anchor.diff:  
           (fun ctx ->
               let provider_key,config = configs |> get_config ctx
  -        
  +
               let extractToken =
                   match config.token_response_type with
                   | JsonEncode -> util.parseJsObj >> Map.tryFind "access_token" >> Option.bind (unbox<string> >> Some)
  
positive.code:             with
                  | OAuthException e -> return! f_failure {FailureData.Code = 1; Message = e; Info = e} ctx
                  | e -> return! f_failure {FailureData.Code = 1; Message = e.Message; Info = e} ctx
          }
negative.code:                     let user_id = user_info.["id"] |> System.Convert.ToString
                      let user_name = user_info.["name"] |> System.Convert.ToString
  
                      return! f_success {ProviderName = provider_key; Id = user_id; Name = user_name; AccessToken = Option.get access_token; ProviderData = user_info} ctx
                  }
          )
  
  