OpenQA.Selenium.ExecutingAsyncJavascriptTest.ShouldBeAbleToExecuteAsynchronousScripts C# (CSharp) Method

        public void ShouldBeAbleToExecuteAsynchronousScripts()
        {
            driver.Url = ajaxyPage;

            IWebElement typer = driver.FindElement(By.Name("typer"));
            typer.SendKeys("bob");
            Assert.AreEqual("bob", typer.GetAttribute("value"));

            driver.FindElement(By.Id("red")).Click();
            driver.FindElement(By.Name("submit")).Click();

            Assert.AreEqual(1, GetNumberOfDivElements(), "There should only be 1 DIV at this point, which is used for the butter message");

            driver.Manage().Timeouts().SetScriptTimeout(TimeSpan.FromSeconds(10));
            string text = (string)executor.ExecuteAsyncScript(
                "var callback = arguments[arguments.length - 1];"
                + "window.registerListener(arguments[arguments.length - 1]);");
            Assert.AreEqual("bob", text);
            Assert.AreEqual("", typer.GetAttribute("value"));

            Assert.AreEqual(2, GetNumberOfDivElements(), "There should be 1 DIV (for the butter message) + 1 DIV (for the new label)");
        }