public void Can_Delete_Hero()
        {
            int id = 3;

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

            mock.Setup(m => m.GetAll()).Returns(new List <Hero> {
                new Hero {
                    HeroId = 1, Name = "Hero1"
                },
                new Hero {
                    HeroId = 2, Name = "Hero2"
                },
                new Hero {
                    HeroId = 3, Name = "Hero3"
                },
            });

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

            List <Hero> heroes = repository.DeleteHero(mock.Object, id);

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