title: I keep getting errors in my code, specifically "Type 'FirstViewController' has no member" and "Use of unresolved identifier"
body: <p>I get errors saying, "Type 'FirstViewController' has no member 'keepTimer'" and "Use of unresolved identifier 'keepTimer'". </p>
  
  <p>What am I doing wrong? How should I change this? 
  My main goal is to have a stopwatch start keeping track of time. When I press Save, it should add the stopwatch value as an event in Calendar.</p>
  
  <p>I have made sure all are identical. They are identical in terms of spelling, but some have () at the end. When I add () at the end, I still get errors.</p>
  
  <pre><code>@IBAction func startButton(_ sender: Any) {
            captureStartDateTime()
          timer = Timer.scheduledTimer(timeInterval: 0.01, target: self, selector: #selector(FirstViewController.self.keepTimer), userInfo: nil, repeats: true)
          keepTimer()
          startOutlet.isHidden = true
      } ...
  
  func keepTimer() {...}
  </code></pre>