public async Task <bool> Remove(string username)
        {
            var user = await CosmosDBRepository <User> .GetSingleItemAsync(x => x.Username == username);

            if (user != null)
            {
                await CosmosDBRepository <User> .DeleteItemAsync(user.Id.ToString());

                return(true);
            }

            return(false);
        }
 public async Task DeleteConfirmedAsync(string id)
 {
     await CosmosDBRepository <Book> .DeleteItemAsync(id, CollectionId);
 }