title: How to check if a shortcut already exists?
body: <p>I have written this method to check if a shortcut already exists for the given id.</p>
  <pre><code>public static func shortcutExists(id: String, completion: @escaping ((Bool) -&gt; Void)) {
          var exists = false
          INVoiceShortcutCenter.shared.getAllVoiceShortcuts { voiceShortcutsFromCenter, error in
              if let voiceShortcutsFromCenter = voiceShortcutsFromCenter {
                  for voice in voiceShortcutsFromCenter {
                      if id == voice.shortcut.intent?.identifier {  // What to do here?
                          exists = true
                          break
                      }
                  }
              } else {
                  ...
              }
              completion(exists)
          }
      }
  </code></pre>
  <p>I have a unique id for each intent entry. But I don't know how to save that ID as intent's identifier. The identifier seems rather readonly and seems to be autogenerated.</p>
  <p>How can I achieve this please?</p>