public void Setup()
        {
            mock = new Mock<IEventRepository>();
            mock.Setup(m => m.Categories).Returns(new Category[]
            {
                new Category { CategoryId = 1, Name = "Hockey" },
                new Category { CategoryId = 2, Name = "A category" },
                new Category { CategoryId = 3, Name = "Other" }
            }.AsQueryable());

            controller = new CategoryController(mock.Object);
        }