UICollectionView: add spacing between header and items
<p>I want to add some spacing between my header and the actual items, which currently look like this:</p>

<p><a href="https://i.stack.imgur.com/32v77.png" rel="noreferrer"><img src="https://i.stack.imgur.com/32v77.png" alt="screenshot1"></a></p>



<pre><code>func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -&gt; UICollectionReusableView {
    // Create header
    switch kind{
        case UICollectionElementKindSectionHeader:
            let headerView = iconCollectionView.dequeueReusableSupplementaryViewOfKind(kind, withReuseIdentifier: "customIconHeaderView", forIndexPath: indexPath) as! CustonIconHeaderView
            headerView.setUp() //add whatever into the view
            return headerView
        default:
            assert(false, "Unexpected element kind")
    }

}
</code></pre>