public void DriverExtension_Wait()
{
var driver = new FirefoxDriver();
driver.Navigate().GoToUrl("http://www.baidu.com");
driver.FindElement(By.Id("kw")).SendKeys("selenium");
driver.FindElement(By.Id("su")).Submit();
driver.WaitTitleContains("selenium");
Assert.True(driver.Title.Contains("selenium"));
driver.Navigate().GoToUrl("http://docs.seleniumhq.org/docs/03_webdriver.jsp");
driver.WaitElementExist(By.Id("additional-resources"));
var ele = driver.FindElement(By.Id("additional-resources"));//接收这个元素，类似于判断
driver.Navigate().GoToUrl("https://www.mozilla.org/en-US/about/");
driver.WaitUnit<bool>(
p => p.FindElement(By.Id("masthead")).Text == "Mozilla");
}