public void When_deleting_a_User_then_the_User_is_deleted_from_simpledb()
        {
            // Arrange
            var UserId = Guid.NewGuid().ToString();
            var simpleDB = MockRepository.GenerateStub<SimpleDBProvider<User, string>>();

            var provider = new AmazonSimpleDbUserProvider(simpleDB);

            // Act
            provider.Delete(UserId);

            // Assert
            simpleDB.AssertWasCalled(db => db.Delete(new[] { UserId }));
        }