title: Trying to understand #selector and what happens with its method requires arguments Swift 3
body: <p>I understand that the #selector(myFunc) only "points" to myFunc.  Let's say I have </p>
  
  <pre><code>UIBarButtonItem(title: "Logout", style: .plain, target: self, action: #selector(handleLogout))
  </code></pre>
  
  <p>and</p>
  
  <pre><code>func handleLogout(shouldAnimate: Bool) {
      present(someController, animated: shouldAnimate, completion: nil)
  }
  </code></pre>
  
  <p>What happens to the parameter shouldAnimate when the bar button item is pressed?</p>
  
  <p>Sometimes I want to animate the view, sometimes I don't.  It depends on whether handleLogout is is called from the button or not.  Is there a better way to accomplish this?</p>
  
  <p>I have looked at many other threads and they all say to use instance variables but I don't understand how that would help me.</p>