title: equivalent of "didAddAnnotationViews" for removing pins?
body: <p>I have a mapview. I've implemented didAddAnnotationViews to show a custom fade in animation for my pins.</p>
  
  <p>This is called successfully when pins are added to the map, but not when pins are removed. I can't find an equivalent function in the documentation. Is there another way to implement a custom fade out animation for specific pins?</p>