e><code class="prettyprint lang-dart">bool sendBeacon(String url, data) {
  if ((data is String || data == null) &amp;&amp; (url is String || url == null)) {
    return _blink.BlinkNavigator.instance.sendBeacon_Callback_2_(unwrap_jso(this), url, unwrap_jso(data));
  }
  if ((data is TypedData || data == null) &amp;&amp; (url is String || url == null)) {
    return _blink.BlinkNavigator.instance.sendBeacon_Callback_2_(unwrap_jso(this), url, unwrap_jso(data));
  }
  if ((data is FormData || data == null) &amp