public async Task AndNoInput_Next_ShowsError()
        {
            await PageSut.ClickOnElementByText("Next");

            PageSut = AsStep <BlueFlowStepB>();

            var errors = PageSut.Errors();

            CollectionAssert.IsNotEmpty(errors);

            Assert.AreEqual("Value cannot be empty", errors.Single());
        }
        public async Task AndInputIsOk_Next_ShowsStepC_ThenPreviousKeptInput()
        {
            PageSut.Input.Value = "Ok";
            await PageSut.ClickOnElementByText("Next");

            await AsStep <BlueFlowStepC>().ClickOnElementByText("Previous");

            PageSut = AsStep <BlueFlowStepB>();

            Assert.AreEqual("Ok", PageSut.Input.Value);
            var errors = PageSut.Errors();

            Assert.IsTrue(!errors.Any());
        }