title: Check which image view was pressed using UITapGestureRecognizer in Swift
body: <p>I have three <code>UITapGestureRecognizers</code>.<br>
  They look like that:</p>
  
  <pre><code>gestureImageViewUp = UITapGestureRecognizer(target: self, action: #selector(ViewController.checkChoice(_:)))
  self.imageViewUp.addGestureRecognizer(gestureImageViewUp)
  
  gestureImageViewDown = UITapGestureRecognizer(target: self, action: #selector(ViewController.checkChoice(_:)))
  self.imageViewDown.addGestureRecognizer(gestureImageViewDown)
  
  gestureImageViewMiddle = UITapGestureRecognizer(target: self, action: #selector(ViewController.checkChoice(_:)))
  self.imageViewMiddle.addGestureRecognizer(gestureImageViewMiddle)
  </code></pre>
  
  <p>I want to check which of them was pressed. How can I solve that?</p>