title: Does setting a button's UIAccessibilityTrait remove the word "button" from it's accessibilityLabel?
body: <p>I ran into a weird situation just now. I have a container view in our app which needs to read out all of the views when tapped, but only one view should be able to be accessed individually. Because some of the views are complex views with their own subviews, I setup my ADA logic to read the accessibilityLabel of a view if it has one, and if not, to build one from the subviews. </p>
  
  <p>Well, today we had to add the word "button" to the help button when it's being read because the container view was tapped. So I simply added the word "button" to the label's accessibilityLabel and everything worked fine. Then I realized, this may change it to read "more information button button" when tapped individually, since I had set the accessibilityTraits property of the button to be <code>UIAccessibilityTraitButton</code>. </p>
  
  <p>However, to my surprise, it read it correctly as "more information button." Does Apple detect extraneous "button's" in an accessibilityLabel and remove them when the trait is set to be a button? Would they also remove extraneous "label's" from a button when it's trait is set to be a label? I find this extremely cool, and incredible forethought on Apple's engineer's parts, if this is the way it works. </p>
  
  <p>Edit: If this is the way it's done, could someone point me to where this is documented? I wasn't able to find it, although I'm currently still working on this fix so I didn't do the most in depth search I could have done.</p>