title: How to apply multiple masks to UIView
body: <p>I have a question about how to apply multiple masks to a UIView that already has a mask.</p>
  
  <p><strong>The situation:</strong><br>
  I have a view with an active mask that creates a hole in its top left corner, this is a template UIView that is reused everywhere in the project. Later in the project I would like to be able to create a second hole but this time in the bottom right corner, this without the need to create a completely new UIView.</p>
  
  <p><strong>The problem:</strong><br>
  When I apply the bottom mask, it of course replaces the first one thus removing the top hole ... Is there a way to combine them both? And for that matter to combine any existing mask with a new one?</p>
  
  <p>Thank you in advance!</p>