title: Angular 4 [Material 2] Karma Test shows Material Components over Karma output
body: <p>i writing an Angular 4 app with Angluar Material 2 as Style Framework.
  When i test my application karma shows some Angular Material Components over the output and it doesn't disappear.</p>
  
  <p><a href="https://i.stack.imgur.com/QAGSs.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/QAGSs.png" alt="enter image description here"></a></p>
  
  <p>it would be nice if i can suppress this.</p>