public void CreateSmartphone()
        {
            var factory = new SmartphoneFactory();
            var obj     = factory.Create();

            Assert.AreEqual("S8", obj.Model);
            Assert.AreEqual("Samsung", obj.Manufacturer);
            Assert.AreEqual(32, obj.Memory);
            Assert.AreEqual(typeof(Smartphone), obj.GetType());
        }
        public void CreateThreeSmartphones()
        {
            var factory  = new SmartphoneFactory();
            var factory2 = new SmartphoneFactory2();
            var obj      = factory.Create();
            var obj2     = factory2.Create();
            var obj3     = factory2.Create();

            Assert.AreNotSame(obj, obj2);
            Assert.AreNotSame(obj2, obj3);
            Assert.AreNotEqual(null, obj);
            Assert.AreNotEqual(null, obj2);
            Assert.AreNotEqual(null, obj3);
        }