title: cancelPreviousPerformRequests does not seem to work in Swift 3.0
body: <p>As the title states, for some reason, the following (simplified) code is not working:</p>
  
  <pre><code>extension InputView: {
  
      func updateTable(text: String) {
              NSObject.cancelPreviousPerformRequests(withTarget: self, selector: #selector(loadPlaces(text:)), object: nil)
            //NSObject.cancelPreviousPerformRequests(withTarget: self)
  
              self.perform(#selector(loadPlaces(text:)), with: text, afterDelay: 0.5)
  
              prevSearch = inputField.text!;
          }
  
      //Private wrapper function
      @objc private func loadPlaces(text: String) {
          print("loading results for: \(text)")
         // locator?.searchTextHasChanged(text: text)
      }
  }
  </code></pre>
  
  <p>I call <code>updateTable</code> every time a user edits a <code>UITextField</code>, which calls <code>localPlaces</code> which calls a function that queries google's online places API (commented out). Unfortunately, the print line in loadPlaces is called after every single call to updateTable. From my visual inspection, it seems there is in fact a delay to the print statements, however, the old calls do not cancel. I've tried looking on a lot of StackOverflow threads but I couldn't find anything updated for Swift 3. Am I calling something incorrectly?</p>
  
  <p><em>PS.</em> If I instead use the commented out, single-argument, <code>cancelPreviousPerformRequests</code>. It works for some reason.</p>
  
  <hr>
  
  <p><strong>Edit:</strong> I have been able to replicate this error in a separate project. So I'm 100% sure that the above code is wrong. If you would like to replicate this error, open up a new iOS project and paste the following code into the default <code>ViewController</code>:</p>
  
  <pre><code>class InputView: UIView {
  
      func updateTable(text: String) {
          NSObject.cancelPreviousPerformRequests(withTarget: self, selector: #selector(loadPlaces(text:)), object: nil)
  
          self.perform(#selector(loadPlaces(text:)), with: text, afterDelay: 0.5)
  
      }
  
      //Private wrapper function
      @objc private func loadPlaces(text: String) {
          print("loading results for: \(text)")
          // locator?.searchTextHasChanged(text: text)
      }
  }
  
  
  
  
  class ViewController: UIViewController {
  
      override func viewDidLoad() {
          super.viewDidLoad()
          // Do any additional setup after loading the view, typically from a nib.
  
          let input = InputView()
  
          for i in 0..&lt;200 {
              input.updateTable(text: "Call \(i)")
          }
      }
  
      override func didReceiveMemoryWarning() {
          super.didReceiveMemoryWarning()
          // Dispose of any resources that can be recreated.
      }
  
  
  }
  </code></pre>