title: When I add a CALayer I to a custom UIView I hide a child UIImageView
body: <p>I'm developing an iOS app with latest SDK.</p>
  
  <p>I have a custom <code>UIView</code> with an <code>UIImage</code> inside. To that custom <code>UIView</code> I will add a gradient layer:</p>
  
  <pre><code>- (void)changeBackgroundWithLayer:(CALayer*)newLayer
  {
      if (_gradientBackground != nil)
          [_gradientBackground removeFromSuperlayer];
  
      _gradientBackground = newLayer;
      [self.layer addSublayer:_gradientBackground];
  }
  </code></pre>
  
  <p>But, when I do that, I can't see the <code>UIImage</code>.</p>
  
  <p><strong>How can I do it to add the <code>CALayer</code> to the <code>UIView</code> and see the <code>UIImageView</code>?</strong></p>
  
  <p>Hierarchy is:</p>
  
  <pre><code>UIView
    |
    ---- UIImageView
  </code></pre>