BingMainPage.cs

public partial class BingMainPage
{
    private readonly IWebDriver driver;

    public BingMainPage(IWebDriver browser)
    {
        this.driver = browser;
        PageFactory.InitElements(browser, this);
    }

    public string Url => @"http://www.bing.com/";

    public void Navigate() => this.driver.Navigate().GoToUrl(this.Url);

    public void Search(string textToType)
    {
        this.SearchBox.Clear();
        this.SearchBox.SendKeys(textToType);
        this.GoButton.Click();
    }
}