private TestParticleSystem particleTest(int appWidth, int appHeight) {

    TestParticleSystem testParticleSystem =
        new TestParticleSystem(50, new Texture(R.drawable.spark));

    testParticleSystem.addGlStatusController(new BlendController(GL_ONE, GL_ONE));

    testParticleSystem.setPos(appWidth / 2, appHeight / 2, -100);

    RotateAnimation rotateAnimation = new RotateAnimation(10000, 0, 360);
    rotateAnimation.setRotateVector(1, 1, 1);
    rotateAnimation.setLoop(true);
    rotateAnimation.setInterpolator(new LinearInterpolator());
    testParticleSystem.startAnimation(rotateAnimation);
    return testParticleSystem;
  }
  private void buttonTest() {
    final ButtonOverlay btn = new ButtonOverlay(R.drawable.image2, R.drawable.mask2);

    // btn.setPos(0, btn.getHeight() + 50);

    RotateAnimation rotate = new RotateAnimation(2000, 0, 360);
    rotate.setRotateVector(1, 0, 0);
    rotate.setLoop(true);
    btn.startAnimation(rotate);
    btn.addGlStatusController(new CullFaceController(BothSide));

    OverlayParent overlayParent = new OverlayParent();

    overlayParent.addChild(btn);

    overlayParent.setPos(btn.getWidth() / 2, btn.getHeight());

    addChild(overlayParent);
  }