title: Same viewController on both iOS and tvOS apps, UIPickerViewDelegate not available on tvOS
body: <p>I am using a ViewController for both iOS and tvOS targets and for iOS I use a UIPickerView.</p>
  
  <pre><code>class FirstViewController: UIViewController,
      UITableViewDataSource, UITableViewDelegate, 
      UITextFieldDelegate,UIWebViewDelegate,
      UIPickerViewDataSource, UIPickerViewDelegate
  </code></pre>
  
  <p>The UIPickerViewDataSource and UIPickerViewDelegate are not available on tvOS, and I'm only using them on iOS, but I get the error <em>UIPickerViewDelegate is unavailable</em> when I try to build for tvOS.</p>
  
  <p>Is there a way to include UIPickerViewDataSource and UIPickerViewDelegate only for iOS app and exclude them when building for tvOS?</p>