title: Use of unresolved identifier: "UNMutableNotificationContent"
body: <p>I have the following code:</p>
  
  <pre><code>func sendLucidNotification() {
      let content = UNMutableNotificationContent()
      content.title = "10 Second Notification Demo"
      content.subtitle = "From MakeAppPie.com"
      content.body = "Notification after 10 seconds - Your pizza is Ready!!"
      content.categoryIdentifier = "message"
  
  }
  </code></pre>
  
  <p>When I call, UNMutableNotificationContent, or any "UNMutableNotification" variation I get the following error:</p>
  
  <pre><code>Use of unresolved identifier: "UNMutableNotificationContent"
  </code></pre>
  
  <p>I'm on Xcode 8.0, but when I try autocompleting it doesn't recognize it either. Any ideas ? Thank you!</p>