title: How big should a UIBarButtonItem image be?
body: <p>I'm looking to create my own custom Sort By Date and Sort By Number buttons that I plan on placing in the navigation bar as the right button.</p>
  
  <p>How big should my image be to appropriately fill the space -- the <a href="https://developer.apple.com/documentation/uikit/uibaritem" rel="noreferrer">UIBarItem</a> documentation page doesn't list anything about the size the image should be.</p>