public void Check_Abstract_Factory_Returns_Correct_Objects()
        {
            AbstractFactory  factory1 = new Factory1();
            AbstractProductA product1 = factory1.CreateProductA();
            AbstractProductB product2 = factory1.CreateProductB();

            Assert.AreEqual(product1.GetType(), typeof(ProductA1));
            Assert.AreEqual(product2.GetType(), typeof(ProductB1));
        }