title: toggling between UIViews that have autolayout
body: <p>I have a screen with a 2 sets of buttons (both sets are inside a <code>UIView</code>) that only one needs to be displayed, and a <code>UICollectionView</code> below them (and tied to one of them in autolayout)</p>
  
  <p>In order to "display" the correct view I'm using<br>
  <code>[self.view bringSubviewToFront:&lt;relevant view&gt;];</code></p>
  
  <p>Everything is OK until I go forward to a different screen and press back.
  I'm getting a weird blank between the buttons view and the <code>UICollectionView</code></p>
  
  <p>It is definitely happens only after "2 replacements" (2 calls to <code>bringSubviewToFront</code>)</p>
  
  <p>So my question is - what is the correct approach in putting 2 views in the same place and choosing the correct one when using autolayout</p>