TestStack.Seleno.BrowserStack.SpecFlowPlugin

 [Binding]
 public class CalculatorSteps
 {
     private SelenoHost _browserHost;
     private readonly DesiredCapabilities _capabilities = new DesiredCapabilities();
     private CalculatorPage _calculatorPage;

     [Given(@"I the (.*) is (.*) on (.*) (.*) for (.*)")]
     public void GivenTheBrowserIs(string browser, string version, string osName,
                                   string osVersion, string resolution)
     {
         _capabilities.SetCapability(CapabilityType.BrowserName, browser);
         _capabilities.SetCapability(CapabilityType.Version, GetValue(version));
         _capabilities.SetCapability("os", GetValue(version));
         _capabilities.SetCapability("resolution", GetValue(resolution));
         _capabilities.SetCapability("os_version", GetValue(version));
         _capabilities.SetCapability("browserstack.user",
                                     ConfigurationManager.AppSettings["browserstack.user"]);
         _capabilities.SetCapability("browserstack.usekey",
                                     ConfigurationManager.AppSettings["browserstack.usekey"]);
         _browserHost = new SelenoHost();
     }

     [Given(@"I navigated to ""(.*)""")]
     public void GivenINavigatedTo(string url)
     {
         _browserHost.Run(config => config
                                     .WithRemoteWebDriver(BrowserStackRemoteDriver(url))
                                     .WithWebServer(new InternetWebServer(url)));
         _calculatorPage = _browserHost.NavigateToInitialPage<CalculatorPage>();
     }

     [Given(@"I have entered (.*) into the calculator")]
     public void GivenIHaveEnteredIntoTheCalculator(int number)
     {
         _calculatorPage.Enter(number);
     }

     [When(@"I press add")]
     public void WhenIPressAdd()
     {
         _calculatorPage.ClickOnAddButton();
     }

     [Then(@"the result should be (.*) on the screen")]
     public void ThenTheResultShouldBeOnTheScreen(int expectedResult)
     {
         _calculatorPage.Result.Should().Be(expectedResult);
     }

     private Func<RemoteWebDriver> BrowserStackRemoteDriver(string url)
     {
         return () => new RemoteWebDriver(new Uri(url), _capabilities);
     }

     private void GetValue(string value)
     {
        return string.IsNullOrEmpty(value) ? "ANY" : value;
     }

     [AfterScenario]
     public void CloseBrowserHost()
     {
        _browserHost.Dispose();
        _browserHost = null;
     }
 }

[Binding]
public class CalculatorSteps
{
   private IBrowserHost _browserHost;
   private CalculatorPage _calculatorPage;

   public CalculatorSteps(IBrowserHost browserHost)
   {
      _browserHost = browserHost;
   }

   [Given(@"I navigated to ""(.*)""")]
   public void GivenINavigatedTo(string url)
   {
       _calculatorPage = _browserHost.NavigateToInitialPage<CalculatorPage>(url);
   }

   [Given(@"I have entered (.*) into the calculator")]
   public void GivenIHaveEnteredIntoTheCalculator(int number)
   {
       _calculatorPage.Enter(number);
   }

   [When(@"I press add")]
   public void WhenIPressAdd()
   {
       _calculatorPage.ClickOnAddButton();
   }

   [Then(@"the result should be (.*) on the screen")]
   public void ThenTheResultShouldBeOnTheScreen(int expectedResult)
   {
       _calculatorPage.Result.Should().Be(expectedResult);
   }  
}