title: How to programmatically set UIStackView to take up 100% of the width and height of the parent view?
body: <p>I cannot have constants, as screen sizes would change the stackview height and width. I want to have one general stackview that has the height and width of the view.</p>
  
  <p>problem is if I get <code>self.view.frame.height</code> gives me 0, which is strange, as I thought I could use that to set the height of the stackView.</p>
  
  <p>This works fine with constants, but of course I need it to be dynamic base don the height/width:</p>
  
  <p><code>parentStack.widthAnchor.constraint(equalToConstant: 414).isActive = true
  parentStack.heightAnchor.constraint(equalToConstant: 250).isActive = true</code></p>