title: How do I dismiss the AirPrint Popover?
body: <p>I have a singleton popover, so that I only show one popover at a time. When I do my share popover, and choose AirPrint, the share popover correctly goes away, showing the AirPrint popover in its place.</p>
  
  <p>But if I press the share button again, the share popover displays on top of the AirPrint popover.</p>
  
  <p>I can't find a way of referencing the AirPrint popover to dismiss it.</p>
  
  <p>Some further information - I have UIBarButtonItems on a toolbar at the bottom of the screen, and four UIBarButtonItems nested inside a navigationBar's rightBarButtonItem at the top of the screen.</p>
  
  <p>The UIBarButtonItems at the bottom of the screen correctly dismiss the AirPrint popover automatically, but the nested ones at the top do not.</p>
  
  <p>But if I knew the name of the AirPrint popover, I could dismiss it from the top buttons' code.</p>