title: Set border in UICollectionView
body: <p>It is my first time that I want to create a UICollectionView. This is how I want it to look like:</p>
  
  <p><img src="https://i.stack.imgur.com/tm2FG.jpg" alt="enter image description here"></p>
  
  <p>I read some tutorials and I know how it works exactly. The thing is as you see in the image, The UICollection cells have border from up, bottom, left and right. Do you know how can set these kind of border in Collection View?</p>
  
  <p>As you see two of the items are selected by red color. is it possible in UICollectionView to have multiple selected items? if yes, could you please give send me some tutorials.</p>