happens if it has a graphic. The misbehavior is 

- memory leak
- NPE (after removing incorrect guard against null in the listener ;) on resize the graphic

culprit is a listener added to the graphic's layoutBounds:

    final InvalidationListener graphicPropertyChangedListener = valueModel -> {
        invalidText = true;
        // fixme: this must not be called after dispose
        /*if (getSkinnable() != null)*/ 
            getSkinnable().requestLayout();
    };

to reproduce the memory leak, add a Label (and all other subclasses) with graphic to the list of controls in SkinMemoryLeakTest. For the NPE, add a test like:

    /**
     * Cleanup graphic listener -
     */
    @Test
    public void testLabeledGraphicDispose() {
        Rectangle graphic = (Rectangle) control.getGraphic();
        installDefaultSkin(control);
        control.getSkin().dispose();
        graphic.setWidth(500);
    }
    
 to fix, remove the listener in dispose