public void GivenRentalRepository_WhenAddRentalToDB_ThenNewRentalInRentalDB()
        {
            //Given
            Rental testRental = new Rental()
            {
                UserId = "LP_21051987", Isbn = "isbnTest"
            };

            //When
            _rentalRepository.AddRentalToDB(testRental);

            //Then
            Assert.Contains(testRental, DBRentals.DBRental);
        }