public async Task <TaggingOperationResult> AddUserToTagsAsync(string userId, List <PNAttributedTag> tags) { List <DynamoSubscriber> subscribers = await subscriberTableOperator.GetAllSubcribersOfUserAsync(userId); if (subscribers.Count == 0) { return(new TagCRUDFailedResult(new UserNotFoundException(userId))); } foreach (var subscriber in subscribers) { await SubscribeToTagsAsync(subscriber, tags); } TagCRUDSuccessfulResult result = new TagCRUDSuccessfulResult(); result.NumberOfModifications = subscribers.Count; return(result); }