public void SetStandardRoom()
        {
            var hotelId   = Guid.NewGuid();
            var hotelName = "The Grand Budapest Hotel";
            var hotel     = new Hotel.Hotel(hotelId, hotelName);

            HotelRepository.Setup(it => it.FindHotelBy(hotelId)).Returns(hotel);

            HotelService.SetRoom(hotelId, 101, RoomType.Standard);


            Assert.Equal(hotel, HotelService.FindHotelBy(hotelId));
        }