title: How to highlight search results in PDFKit - iOS
body: <p>I use PDFKit for iOS 11, using search functions, i got some <code>PDFSelection</code> elements. How to highlight the text corresponding to this selection in the PDF?</p>
  
  <p>I tried with this, but isn't working :</p>
  
  <pre><code>selection.color = UIColor.red
  selection.draw(for: selection.pages.first!, active: true)
  </code></pre>