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