public void Can_Delete_Zone()
        {
            int id = 3;

            Mock <IRepository <Zone> > mock = new Mock <IRepository <Zone> >();

            mock.Setup(m => m.GetAll()).Returns(new List <Zone> {
                new Zone {
                    Id = 1, Name = "Zone1"
                },
                new Zone {
                    Id = 2, Name = "Zone2"
                },
                new Zone {
                    Id = 3, Name = "Zone3"
                },
            });

            //BookRepository repository = new BookRepository();
            TestHelps repository = new TestHelps();

            List <Zone> zones = repository.DeleteZone(mock.Object, id);

            Assert.AreEqual(2, zones.Count);
        }