title: Setting the system volume in Swift under IOS
body: <p>Ok, </p>
  
  <p>This gets the system volume, works well. </p>
  
  <pre><code>var volume = AVAudioSession.sharedInstance().outputVolume
  print("output volume: \(volume)")
  </code></pre>
  
  <p>But how do I set the system volume [in Swift] please</p>