title: How Can I have multiple widths and heights of subviews in a UIStackView
body: <p>Say for example I want to add 3 buttons to a stack view.</p>
  
  <p>Button1 is 200 * 200  (1)</p>
  
  <p>Button2 is 150 * 150  (0.75)</p>
  
  <p>Button3 is 100 * 100  (0.5)</p>
  
  <p>How can I accomplish this in interface builder?</p>