title: Speadsheet.getRangeByName is undefined
body: <p>According to the <a href="https://developers.google.com/apps-script/reference/spreadsheet/spreadsheet#getRangeByName(String)" rel="nofollow noreferrer">documentation</a>, there is a function named <code>getRangeByName(String)</code> in class Spreadsheet but it seems to be undefined for me.</p>
  
  <pre><code>function onEdit(e) {
      if (e) {
          var ss = e.source.getActiveSheet();
          Logger.log(ss.getName);  
          Logger.log(ss.getRange);
          Logger.log(ss.getRangeByName);
      }   
  }
  // outputs:
  //  function getName() {/* */}
  //  function getRange() {/* */}
  //  undefined
  </code></pre>
  
  <p>Is this because <code>event.source.getActiveSheet()</code> returns something else other than a <code>Spreadsheet</code> object, which contradicts the official documentation (screenshot)? </p>
  
  <p><img src="https://i.stack.imgur.com/B3SjD.png" alt="enter image description here">(<a href="https://developers.google.com/apps-script/understanding_events" rel="nofollow noreferrer">https://developers.google.com/apps-script/understanding_events</a>)</p>
  
  <p>If that's the case, how can I get a range by name on the active sheet from the event's source? Thanks.</p>