title: Motion/Material Unbalanced calls to begin/end appearance transitions
body: <p>I'm using latest version Material library for Swift (2.16.0). And in my project I have NavigationDrawer controller with ToolBarController as root view controller. Then I try to present modally SearchBarController, motion animation worked perfectly</p>
  
  <pre><code>let searchController = AppStoryboard.Tree.viewController(viewControllerClass: SearchViewController.self)
  let searchBarController = SearchBarController(rootViewController: searchController)
  searchBarController.isMotionEnabled = true
  searchBarController.motionTransitionType = .autoReverse(presenting: .fade)
  toolbarController?.present(searchBarController, animated: true)
  </code></pre>
  
  <p>But in log I see messages:</p>
  
  <pre><code>Unbalanced calls to begin/end appearance transitions for &lt;Material.SearchBarController: 0x7f8db554bde0&gt;.
  Unbalanced calls to begin/end appearance transitions for &lt;NavigationDrawerController: 0x7f8db680b000&gt;.
  </code></pre>
  
  <p>I know, that Motion library have <code>transition(to: &lt;UIViewController&gt;)</code> method. But this method does not work for me, because it replaces the <code>rootViewController</code> </p>