title: Error cannot convert return to type uiviewcontroller
body: <p>i used <a href="https://github.com/12207480/TYPagerController" rel="nofollow noreferrer">TYPagerController</a> , i trying to show view controller and i have an error </p>
  
  <blockquote>
    <p>cannot convert return expression of type [uiviewcontroller] to return type 'UIViewController'</p>
  </blockquote>
  
  <pre><code>func tabPagerController(_ tabPagerController: TYTabPagerController, controllerFor index: Int, prefetching: Bool) -&gt; UIViewController {
    let storyboardName = "Main"
    let storyboard = UIStoryboard(name: storyboardName, bundle: Bundle.main)
      var viewControllers = [UIViewController]()
          let categoryCV = storyboard.instantiateViewController(withIdentifier: "homeToCategory") as! CategoryViewController
              viewControllers.append(categoryCV)
          let featuredCV = storyboard.instantiateViewController(withIdentifier: "FeatureViewController") as! featuredViewController
              viewControllers.append(featuredCV)
  
      return viewControllers
  }
  </code></pre>