public void TestAvailability()
        {
            var classroomRepository = new TestClassroomRepository
            {
                //Given
                Courses = new List <Course>
                {
                    new Course()
                    {
                        Week       = 1,
                        WeekDay    = 1,
                        StartBlock = 2,
                        EndBlock   = 5,
                        Rooms      = new List <Classroom>()
                        {
                            new Classroom
                            {
                                RoomId = "H.1.110"
                            }
                        }
                    },
                    new Course()
                    {
                        Week       = 1,
                        WeekDay    = 1,
                        StartBlock = 7,
                        EndBlock   = 9,
                        Rooms      = new List <Classroom>()
                        {
                            new Classroom
                            {
                                RoomId = "H.1.110"
                            }
                        }
                    }
                }
            };
            var bookings          = new List <Booking>();
            var bookingRepository = new TestBookingRepository(bookings);

            var service         = new BookingService(bookingRepository, classroomRepository);
            var existingLessons = classroomRepository.GetCoursesByRoomAndWeek("H.1.110", 1);

            //When
            var booking1 = GenerateBooking("H.1.110", 1, 1, 1, 1);  // 1-1 out 2-5 and 7-9 -> 0
            var booking2 = GenerateBooking("H.1.110", 3, 5, 1, 1);  // 3-5 in 2-5 and under 7-9 -> 1
            var booking3 = GenerateBooking("H.1.110", 3, 9, 1, 1);  // 3-9 in 2-5 and 7-9 -> 2
            var booking4 = GenerateBooking("H.1.110", 8, 10, 1, 1); // 8-11 out 2-5 and in 7-9 -> 1

            //Then
            var availability1 = service.CourseAvailability(existingLessons, booking1);

            Assert.AreEqual(0, availability1.Count, "A1 failed");

            var availability2 = service.CourseAvailability(existingLessons, booking2);

            Assert.AreEqual(1, availability2.Count, "A2 failed");

            var availability3 = service.CourseAvailability(existingLessons, booking3);

            Assert.AreEqual(2, availability3.Count, "A3 failed");

            var availability4 = service.CourseAvailability(existingLessons, booking4);

            Assert.AreEqual(1, availability4.Count, "A4 failed");
        }