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