.events.TriggerEvent.TRIGGER,
          this.button_triggerHandler
        );
        this.addChild(this.button);
      }

      button_triggerHandler = (event) => {
        feathers.controls.TextCallout.show("Hello World", this.button);
      };
    }

    var stage = new openfl.display.Stage(0, 0, null, HelloWorld, {
      allowHighDPI: true,
    });
    document.body.appendChild(stage.element);
  </script>
</body>

</html>