title: dispatch_after in swift explanation
body: <p>I am currently working on a project and for a part of it I need to unhighlight a button after a set period of time. I decided to use <code>dispatch_after</code>.</p>
  
  <p>I have managed to get it working, but can someone please explain me how this line of code exactly works? I have been unable to understand how <code>dispatch_after</code> exactly works.</p>
  
  <pre><code>dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(1000 * Double(NSEC_PER_MSEC))), dispatch_get_main_queue()) {
  
                  self.redButton.highlighted = false
  
              }
  </code></pre>