public void GivenCinemaShowWithoutAvailableSeats_WhenGetAvailableSeats_ShouldReturnNull()
        {
            // ARRANGE
            var cinemaShow = _fixture.Create <CinemaShowDTO>();

            _cinemaShowRepositoryMock.Setup(r => r.GetCinemaShow(It.IsAny <string>())).Returns(cinemaShow);

            _seatRepositoryMock.Setup(s => s.GetAvailableSeats(cinemaShow.Id)).Returns(() => null);

            // ACT
            var seatService = new SeatService(_seatRepositoryMock.Object, _cinemaShowRepositoryMock.Object, _mapperMock.Object);
            var response    = seatService.GetAvailableSeats(cinemaShow.Name);

            // ASSERT
            response.Should().BeNull();
        }