internal static async void FinishRequest(string url, long milliseconds, Exception exception)
 {
     await Task.Run(() =>
     {
         try
         {
             OnRequestFinished?.Invoke(url, milliseconds, exception);
         }
         catch (Exception)
         {
         }
     });
 }
 /// <summary>
 /// Invoke OnRequestFinished event.
 /// </summary>
 /// <param name="restResponse">Rest response.</param>
 private void Callback(IRestResponse restResponse)
 {
     OnRequestFinished?.Invoke(restResponse);
 }