title: Drop Item into an empty Collection View secion
body: <p>I'm working with UICollectionView and Drag/Drop Delegates. I need to drop a data source's item into an empty section. I've learned about that and I found out that it's a long-ongoing trouble (e.g. <a href="https://developer.apple.com/forums/thread/114010" rel="nofollow noreferrer">https://developer.apple.com/forums/thread/114010</a>). But I noticed potential solution in iOS Messages on iOS 15:</p>
  <p><a href="https://i.stack.imgur.com/yQe2R.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/yQe2R.png" alt="enter image description here" /></a></p>
  <p>I tried to do similar placeholder but I don't which class it is. Any ideas? Thanks in advance.</p>