title: remove all subLayers from a view
body: <p>In an animation I added a lot of <strong>sublayers</strong> to a <strong>view</strong>, with:</p>
  
  <pre><code>[self.view.layer addSublayer:layer1];
  [self.view.layer addSublayer:layer2];
  </code></pre>
  
  <p>....</p>
  
  <p>I would like to remove all sublayers with an action.
  I already tried with this suggestion of a similar question:</p>
  
  <pre><code>rootLayer.sublayers = nil;
  </code></pre>
  
  <p>but it doesn't work...</p>
  
  <p>Could you help me?
  Than you!</p>