title: The Origin viewcontroller's weird behavior when it presents new landscape Viewcontroller
body: <p>I setup one portrait Viewcontroller(referred to as PVC) presenting a landscape Viewcontroller(referred to as LVC).
  When the PVC actually presents the LVC, the LVC shows above the PVC and works fine, but PVC's collectionView re-calculates cell size 'unintentionally' and collapses its view.</p>
  
  <p>Here's what I did:</p>
  
  <ol>
  <li><p>In the Xcode settings, I allowed portrait and landscape orientation for having one LVC and other PVCs in the app.</p></li>
  <li><p>I made one Viewcontroller overriding supportedInterfaceOrientations method returning '.landscape' and other Viewcontrollers returning '.portrait'.</p></li>
  </ol>