inner.getStyleClass().add("container");
inner.getChildren().add(downArrowBtn);
getChildren().add(inner);
tabPane.sideProperty().addListener(new InvalidationListener() {
@Override public void invalidated(Observable valueModel) {
Side tabPosition = getSkinnable().getSide();
downArrow.setRotate(tabPosition.equals(Side.BOTTOM)? 180.0F : 0.0F);
}
});