title: How to pass optional parameters while omitting some other optional parameters?
body: <p>Given the following signature:</p>
  
  <pre><code>export interface INotificationService {
      error(message: string, title?: string, autoHideAfter?: number);
  }
  </code></pre>
  
  <p>How can I call the function <code>error()</code> <em>not</em> specifying the <code>title</code> parameter, but setting <code>autoHideAfter</code> to say <code>1000</code>?</p>