public virtual Task <PersonGroup> GetPersonGroupAsync(string personGroupId)
 {
     return(PolicyService.ExecuteRetryAndCapture400Errors(
                "FaceService.GetPersonGroupAsync",
                ApiKeys.FaceRetryInSeconds,
                () =>
     {
         var result = FaceRepository.GetPersonGroupAsync(personGroupId);
         return result;
     },
                null));
 }