title: How to make a portion of an UIImageView transparent in order to show views in layers below
body: <p>Here is a photo explanation to better illustrate what I mean:</p>
  
  <p>I have two <code>UIImageViews</code>, with <code>View1</code> being on the bottom and <code>View2</code> at the top:</p>
  
  <p><img src="https://i.stack.imgur.com/Z4nJa.png" alt="enter image description here"> <img src="https://i.stack.imgur.com/fm6Hr.png" alt="enter image description here"></p>
  
  <p>What I would like to do accomplish is to programmatically set an area on <code>View2</code> that is completely transparent (i.e. has an <code>alpha</code> of <code>0</code>), so that this will be the end result:</p>
  
  <p><img src="https://i.stack.imgur.com/21n30.png" alt="enter image description here"></p>
  
  <p>I haven't been able to find a similar problem related to marking a part of a UIImageView transparent in the form of a shape (specifically, a circle), and was wondering how I should tackle this problem?</p>
  
  <p>Thanks!</p>